I _thought_ I knew a lot about capital gains taxes until filing my own taxes this year.

After firmly boarding the tax-loss harvesting hype train, I had fallen prey to the intuitively appealing idea that short-term capital losses could offset gains from the sale of a rental property held for less than one year. It turns out that short-term gains from the sale of business property flow (Form 4797) directly to your Schedule 1, without an opportunity for Schedule D losses to offset them.

Now as a result I'm sitting on a 5-figure tax bill and 6-figure capital loss carryforward.