I have an idea but I want to check if I'm missing anything.

First, a couple of fundamental facts:

1) Stock gains are taxed once you sell your holdings, with the amount of tax determined by your tax bracket.

2) Your tax bracket is determined by your income from the year you sell.

3) For example, if you are single with an income under $40k in the year in which you sell, you pay 0% on any stock gains (long term gains only), no matter how big those gains are, and even if you made $100k the year before and $100m the year after you sell.

THEREFORE...

If your income is under $40k but might rise in a future year, you can save money by selling all your holdings and then buying them right back (waiting a month by law).

Once you eventually sell again, you would only pay taxes on the amount they rose from now, not when you originally bought them.

Any caveats that may make this idea a bad one? Let me know!