The Best Day To Invest


best day to invest

By now most of you know that I automate 90% of my investing in passive index funds.  The other 10% of my portfolio is in stocks that I like.  I know that trading stocks can be a fruitless proposition, but I’ve been able to beat the market over the last couple of years.  More than anything, I have fun doing it.  With that said, 10% is such a small amount, so it barely makes a ripple in my overall portfolio.  


Dollar-Cost Averaging

best day to investSpecifically, the remaining 90% of my investments are automated into the Vanguard 500.  I’m a big fan of dollar-cost averaging and not trying to time the market.  I strongly subscribe to the maxim that it’s “time in the market, not timing the market”, which yields positive investment returns.  When I get too cute, I start second guessing myself and then the cash piles up.  By then, I’m too afraid to do something because I’m chasing those returns.  


Since I don’t time the market, I did wonder if there was any benefit in which day that I automated my investments.  Most people probably say the best day to automatically invest is the day that you receive your paycheck.  That way you don’t have to worry about when the investment occurs.


So let’s say that you have a $100 to invest for the month.  You can either invest the $100 all in one day or spread it over four weeks during the month.  Which would make more sense?  


The Market’s Best and Worst Days of the Week

best day to investA study by the Journal of Economics and Finance, “The Day of the Week Effect on Stock Market Volatility” reviewed 25 years of daily S&P 500 data and concluded that Wednesday was the best day for the stock market.  On average the stock market went up by 0.032% on this day.


So that settles it, should I buy on Wednesday?  Sure, if you want to buy at the top of the market.  Monday has historically been the worst for stocks based on the day of the week.  It’s actually the only day of the week that had a negative return, -0.0028%.  Investors are constantly encouraged to buy low and sell high, so buying on the worst day of the week would be a good idea.


Why Mondays?

best day to investIt got me thinking, why is it that Mondays are the worst performing day?  Then I thought about it, and the light bulb went off.  Companies, like politicians, like to dump bad news on Fridays after the market has closed, when they think nobody is paying attention.  By the time Monday comes around, the market has had time to digest the news and make a correction to the stock.  


Best Day of the Month

Okay, so now that we know that Monday would theoretically be the best day to buy if we were dollar-cost averaging on a weekly basis.  What would be the best day if we were buying once a month?  


best day to investIn my research I found that stocks perform better towards the end of the month and the very first day of the month.  This is because many U.S. workers are paid on the 30th, 31st or 1st.


Morningstar cited a paper in the Fall 2006 issue of The Journal of Wealth Management, by John Paglia and Xiaoyang Jiang, who studied the stock market’s performance from Jan. 1, 1990, to Dec. 31, 2005.  They concluded that the best day of the month to invest was the 23rd.  


Changing When You Invest

best day to investSo, now it’s settled.  We now know the best weekday and the best day of the month to invest.  Should you totally redo how you are currently doing things?


In The Only Guide to a Winning Investment Strategy, Larry Swedroe says:


“If you had invested the same amount on January 1 of every year for 30 years beginning in 1965, your return would have been 11 percent per annum. If you had been unlucky enough to have invested the same dollar amount each year on the day that the S&P 500 Index hit its peak for that year, your return would still have been 10.6 percent per annum. That is less than a 0.5 percent per annum difference in returns. And no one is that unlucky.

If, on the other hand, you were lucky enough to have chosen the market’s low for the year, each year, then your return would have only increased to 11.7 percent per annum. That is an incremental return of just over 0.5 percent per annum. And no one is that lucky. If that does not qualify as much ado about nothing, I do not know what would.”


His advice is straightforward; “The best time to invest is always whenever you have fund available to do so.”


So readers, when do you invest in the stock market?  Any other ideas about when the best time to make your deposit?  Share your thoughts below.

Mustard Seed Money

Welcome to the website. A mustard seed is a very small seed but astonishingly grows very large over time. My hope is that through your financial journey that your small investment in time, money and faith will grow beyond anything that you could ever imagine.


  1. Interesting statistics. I get my salary on the 26th of the month and transfer the amount that I wish to invest on the same day. So I usually do all my purchases around the end of the month, but probably a bit before the US payday rush 🙂 I have never checked the exact day of the week though. Maybe I should tend towards Mondays…?
    Roadrunner recently posted…The Biggest Dividend Investing MistakeMy Profile

    • I thought some of the studies were really interesting. I guess if I had to choose any day of the week it would be Monday but like they said, it’s basically statistically insignificant.

  2. Interesting post. I invest automatically into my 401k and into my after-tax account twice a month. I’ve never really thought about the day of the week. In my after-tax account, there’s always a lag as it takes time for the funds to get transferred to my investment account and then to invest them.

    The theories in your post make sense. The market is a fickle place. By Wednesday, we’re over the bad news that came out over the weekend and are optimistic once again. That is until the next round of bad news comes out.

    I definitely agree that the best time to invest is when you have the money to do so. Time in the market outperforms timing the market. Happy investing!
    Go Finance Yourself! recently posted…Cut the Cord For Financial FreedomMy Profile

    • Thanks for sharing Go Finance Yourself!!! I think you are like most of us in that we’re automatically invested and don’t give too many thoughts to the market. I actually believe my deposits go in on Wednesday which as long as it goes in I’m happy with 🙂

  3. I’ve been debating whether to just throw the entire max in my Roth IRA right now or use dollar cost averaging on a weekly or monthly basis instead. So, I’m going to need you to go back and tell me the month as well, lol! But really, that’s great advice-time in>timing. I should probably just do it :).
    Making Your Money Matter recently posted…RE402: Qualified Retirement AccountsMy Profile

  4. Mostly, I’ve been putting new money in index funds and have all my individual stocks on automatic reinvestment. I guess I could try timing the investments, but they don’t charge the same fees if you just reinvest, and the method’s worked pretty well for me as an automated investment plan.
    Emily Jividen recently posted…30 More Simple Ways to Save MoneyMy Profile

  5. Very interesting stats MSM. I must admit that I am guilty of trying to time the market for my taxable account. I have a watch list of stocks that I want to buy and have a price target in mind. When those stocks drop close to my target price, my finger starts to itch and wants to pull the trigger on that elephant gun.

    I have a similar thought on how to get the best returns, “it’s not when you buy, it’s when you sell” that determines your return. This has to do with the view that people tend to sell when the market is low for fear of losing more money. I try to remind myself not to sell when the market is low. Instead, buy more when it’s low. That’s when I time the market.
    Leo T. Ly @ isaved5k recently posted…The First Step To Saving A Million DollarsMy Profile

    • Thanks for sharing. I can definitely hear that realtors mindset in your answer 🙂 I have to admit that I keep a small amount of cash available in case the market drops by 20% but for the most part automated investing is the easiest way for me 🙂

  6. The other reason I suspect for Monday’s performance would be when do paychecks come in? Typically Fridays. So 401Ks would theoretically be dumping into stocks on Mondays. Supply and demand after all, you have a larger demand on average on a specific day. Still I tend to invest via dollar cost averaging. Even if Mondays tend to be better the odds are not high that this particular Monday will be better then Tuesday. Average in this case doesn’t show you the correlation, which I imagine is quite low or everyone would be doing it.

    • You are right that the average doesn’t show correlation. If anything that I thought it was interesting the breakdown between the days even if it doesn’t mean much. 🙂

  7. Fascinated info at the close of this article. Didn’t realize the return spread was so small when comparing investing on best and worst days over time. I too am a big advocate of dollar cost averaging and just setting up an automated investment schedule. Every month, money gets invested into the allocation of ETFs I’ve chosen. I don’t even need to think about it and that keeps my monkey mind away from things a little bit too!
    Freedom 40 Guy recently posted…Planning for the Unexpected – The Rainy Day FundMy Profile

    • Dollar cost averaging is definitely the way to go and something that I wish I had started out doing from the get go. I guess that’s why you live and learn 🙂

  8. Wow those are some very interesting statistics! I’ve never even thought about which day to invest under dollar cost averaging. I usually just put money into the market when I receive the paycheck .

    Typically, I don’t invest until the later half of the month because it takes a while for a 401K contribution to get through. I think its like 3 – 4 business days (it feels like forever).

    I might have to consider these findings next month 🙂
    Andrew recently posted…5 Reasons Why You Should Get A Side HustleMy Profile

    • Thanks for sharing Andrew!!! That’s interesting that you invest in the later half of the month based on your 401k. You’ll have to share what you end up doing 🙂

  9. I mean, at least 10% of your portfolio is stocks in case everything goes to hell. It’s another thing entirely if you had a 90% stock portfolio. 😉 Huh, it’s good to know that Wednesdays are traditionally high; that’s so weird. I could see it being low on Monday; everyone is exhausted and tired. I never considered timing of investments, but that makes complete sense since the stock market is so volatile.
    Mrs. Picky Pincher recently posted…What’s In Your Purse?My Profile

    • I definitely thought it was interesting that Wednesday had the biggest returns. I tried to think of what would make it higher but haven’t been able to crack the code yet 🙂

  10. My guess is that 99% of people probably invest on Friday or Monday. You get paid on Friday, and if it your contributions move quickly, then you’re invested by the end of Friday (that’s how my contributions typically are done). If they’re slower, you probably get your 401(k) contributions invested on Monday. Do it like that and I think you’re following the advice of investing whenever you have the funds!
    Financial Panther recently posted…Wealth Is Relative – Remember This And Be HappierMy Profile

    • I definitely agree. I get paid on Thursday but for whatever reason I think my 401k contributions go in on Wednesday. So I’m just happy that they go in every two weeks without a glitch 🙂

  11. I recall an article I read where the author picked an index (SP500 for example). Using historical data, he picked the lowest closing price of the index for the year. He calculated what the return would have been if he had invested once per year on the lowest priced day of the year. He compared that to DCA on the first business day of the month; i.e. $1200 one day per year vs $100 x 12 days per year. He found the one day per year slightly outperformed 12 monthly installments. He assumed reinvested dividends which gave monthly an edge. He ignored trading fees. Finally he noted, he had perfect hindsight whereas the real-world investor doesn’t know if today is the lowest priced day of the year.

    I also recall a long stretch where the indices would dip due to end-of-session sell off. I have heard various explanations. When the market is up, people are selling at the end of day to lock in their gains. When the market is down, mutual fund companies have a day’s worth of sell orders they need to transact at close of business prices. I’m sure someone has done analysis in this area.

    • I definitely wish I had perfect insight. I would invest only on those days and sip pina coladas at the beach for the rest of the year. Hindsight is always easier looking back. I think that’s why so many people got crushed during the great recession.

  12. Dollar cost averaging is absolutely the way to go, I also got cute and tried to time the market a few years back. Hasn’t worked out so great for me. I do wonder however if anyone has done a detailed analysis on timing the market relative to the CAPE ratio. Investing heavy during low periods, and backing off slightly during high periods, and what the results would look like over a 30 year period compared to standard dollar cost averaging throughout.
    Max Your Freedom recently posted…How to Treat your FrugalityMy Profile

    • I have to admit I’m not as familiar with the CAPE ratio as I should be. I take a look and see how much research has been done to see if it makes any difference. Although I have a feeling that if it worked some best selling author would be peddling it.

  13. It is pretty neat to know what days are good for the market and which days aren’t. The most surprising part to me is investing on the best days and worst days is only a swing of 1%, and they are both within ~0.5% of the average. Crazy! I concur that time in the market is better than timing the market. Thanks for putting these great stats together.

  14. Interesting points, especially at the end in regards to investing at the peak or the trough.

    My 401k contributions are automatic and I really have no control on the specific day it gets invested. Same with my HSA. I tend to fund by backdoor Roth via lump sum at the beginning of the year rather than DCA it. For my taxable account, I haven’t quite automated that yet but will probably set something up at the beginning of the month, maybe the 1st or 2nd. I really just ascribe to the notion of “time in the market.”
    SomeRandomGuyOnline recently posted…Real Estate Lessons From Mama and Papa SRGOMy Profile

  15. ” like to dump bad news on Fridays after the market has closed, when they think nobody is paying attention.”

    I never thought about this. Once I’ve finalized research on a stock, I will usually pull the trigger whichever day it’s down compared to it’s previous day. but I guess I should experiment with Monday. Why not get more bang for my buck I suppose?
    SMM recently posted…Financial Goals For 2017My Profile

    • I have to admit that I started researching because I was getting ready to set up a brokerage account with Vanguard and I was trying to see if it made more sense to do it once a month or every week on a certain day. But I found it really doesn’t make much of a difference 🙂

  16. This post is quite “timely” for me as I endeavor to work my way out of the large cash balance mistake I made with my portfolio over the last few years. Regardless of the overall market performance, I will be doing a lot of buying this year – perhaps on Monday’s! Thanks for another great post MSM.
    Zero recently posted…2016 Year in ReviewMy Profile

  17. Very fascinating! It seems like Friday is the usual buying day for me for some reason. No real reason why I guess but that is when I usually do it if I think back on it. I’m going to have to start tracking Monday market performance now! 🙂
    Mr Defined Sight recently posted…Happy Inauguration Day!My Profile

  18. Great data. Thx for sharing with us!

    I have a goal in place to optimize my monthly investments during 2017. Things like this help… It odes not really matter when you invest. Investing matters
    Amber tree recently posted…My 2017 GoalsMy Profile

  19. I must say that I am also a big proponent of NOT timing the market. I, do, however fall prey to checking my investments way too often. At least I did in 2016. One of my goals for this year is to NOT open up my personal capital app every morning. I think I can, I think I can, I think I can. 🙂

    • Thanks for sharing Mrs. Mad Money Monster!!! I have scaled way back on checking my account but I still need to scale it back even more. At this point I figure I check at least once a week. Even though it doesn’t make a difference the way that I invest.

  20. I just put my monthly IRA contribution in today (Monday) before reading the article and the market happens to be down at the moment.

    We have our normal investment contributions withdrawn on the same date each month, but, I might consider doing extra buys on Monday. Which usually tends to be the case as I use my free time on the weekend to research new funds I might want to buy.

    I’m in the process of rebalancing our retirement accounts so I will be moving between several index funds & ETFs in the near future.
    Josh @MoneyBuffalo recently posted…Jet vs BoxedMy Profile

    • Thanks for sharing Josh!!! That’s interesting that you decided to buy today 🙂 Coincides nicely with the article. You’ll have to share if you end up doing some extra buys on Mondays.

  21. Straight-forward and simple advice can be best so I agree with Larry!
    Having said that I’ll get in there and say Monday due to it being the day where most people are probably unhappy with their jobs 😉
    Having said that I also agree with my mate DC about people selling hard due to being anxious over the weekend

    • Thanks for stopping by and sharing Jef!!! You are probably right, people probably dread Monday and think about altering their portfolio to optimize it. Smart thought process 🙂

  22. Wow, this is interesting. I like to fund a big portion of my IRA (2/3rds) in the beginning of the year and then the save the balance for the very last possible day….. i.e. right before tax day. I just like to know that some of that is liquid in case the stock market does a crazy crash or something and I can jump in. Probably not worth it though. 🙂
    Primal Prosperity recently posted…“Some Travel, Others Journey”My Profile

    • Thanks for sharing Primal Prosperity. I normally get all my money in on the first day available and then just dump it in the market. I figure why not get four quarters of dividends 🙂

  23. Interesting read. I have to be honest. I never gave any thought to what day or time of the month. I just have mine set up to automatically withdraw from my savings once a month. After reading this, I am going to give it more thought and make some adjustments. It makes total sense to invest in the way that will give you more “bang” for your buck.,

    • Thanks for sharing Susan!!! I have to admit that I was somewhat shocked to read that Mondays were always the lowest. Based on yesterday’s performance, short term bias, it held true 🙂 You’ll have to share what you end up doing.

  24. This is a great article. One that I have always thought I should figure out. Lately I have been allocating at least $1000 and then buying one of my target stocks 2 days before the x dividend date. This way ensures everything has been processed and I will receive their next dividend payment. Ironically most x dividend dates I have been buying are on Friday’s so I tend to be buying Wednesday’s Woot!

    • Hahahha!!! Sounds like you have been buying on a good day. I have to admit I was shocked to see that Monday was the best day but when you think about it makes sense. People are adjusting portfolios on the weekend and a lot of bad news is released on Friday 🙂

  25. I like your analysis of why the different periods perform better. I was recently pondering why “sell in May and go away”. Although I have no data to officially back it up, I’m wondering if the reason is because everyone is investing before tax season in January-April — so money keeps flowing into the market. After tax day everyone stops adding money and the summer ends up slumping from the spring surge.

  26. This has me really curious to find the best month of the year… Even though I know it will be statistically insignificant, especially if you’re holding on to cash for months to wait for that “prime time” I love the data! I assume January operates similarly to the end of the month, people investing year end bonuses en masse.

    Thanks for an interesting post! I DCA everything, except bonuses which get dumped in when they arrive. Love the data 🙂
    Chelsea @ Mama Fish Saves recently posted…Book Review – The Behavior GapMy Profile

  27. So let’s put some numbers into the generalities you are discussing here. If you invest $667/month over 30 years (assuming an annual income of $100,000 and the ability to invest 8% pretax) at the “worst” return of 10.6% you would have $1,869,679 to retire on. If you were able to realize that “only .4%” additional return it would be worth an extra $154,609 at retirement, so you can see that there is definitely power in “timing the market”. But what about the more sure bet? Time IN the market – where an additional 5 years 35 vs 30 would grow that “I’ll timed” $1,869,679 to $2,959,493! Who would like an extra million dollars to retire on? You’re welcome.

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