Offer your thoughts or opinion on the input financial query or topic using your financial background.

Investment time horizon: When is it acceptable to withdraw money from investments?
shouldn't withdraw stock investments for at least 5 years would be better re-phrased as: "don't invest money in stocks if you (really) need it within next few years". The underlying principle is: stocks are one of the higher-risk investment classes out there.  While that's exactly what you want over a long time horizon (longer than the ebb and flow of the broader economy); if you know you'll definitely have to withdraw $50k (or any large chunk) of it within just a few years, it's possible that a great long-term vehicle like stocks, could actually rob you of money on a shorter time horizon. So if you want to start a business 2 years from now, you'll probably want to retain some of that $300k initial pile in lower-risk investment vehicles (e.g. bonds, CDs, certain ETFs and mutual funds aimed at "capital preservation", etc). That said, interest rates are so low, that if you're flexible with how much money you'll need to start that business, I'd probably keep as much as you can stomach in diversified stocks (per your original plan).