Should a long-term transaction (a capital loss in my case) not reported to IRS be usable to offset long-term capital gain? I provided all these information to TurboTax, and it seems the "not reported" amount is ignored, resulting in about $1600 taxable gain, instead of $3000 loss.
The unreported amount is related to a sale of RSU vested a few years ago. Back then, the full amount was taxed. So, I could consider that as a virtual transaction in which my company gave me extra income equal to the market value of the RSU, and I used that to buy company's stock. On the 1099-B form, cost-basis is 0. But adjusted cost basis reflects the market value at vesting time.
In short, I'd two stock sales, one is reported in box-D (reported), which is a long-term gain. The other is reported in box-E (not reported), which is a long-term loss. Turbo tax seems to ignore my loss. What is the reason?