It's not a tax incentive though - an incentive encourages you to do something, nobody is encouraged to
lose money. Also, if one were to do the above, and the growth fund went up, you'd wind up paying taxes on that gain which would offset the tax deduction you took on the loss when you eventually sold it, whereas you could have just stayed in, waited for it to go back up, and you'd be at a wash.
If someone followed your advice exactly and sold on day 364 vs staying in they'd lose even more, as by the time the initial investment goes back up (after day 365) you'd be in long-term capital gains territory, which is a lower tax rate.
That's why I said it only works in the short term - eventually the gov't is gonna get it's money.
