Cost Basis and Tax LotsEvery buy opens a tax lot: a quantity acquired on a date at a cost. Sells close lots FIFO (first in, first out) by trade date — and because matching is by trade date, a statement imported newest-first cannot close a lot before it was opened.
Viewing lots
The Portfolio workspace's Tax Lots tab shows each open lot per security and account: acquired date, remaining quantity, cost basis, current value, and gain. (Crypto acquisitions open lots through the same machinery — see Crypto.)
Unknown basis is reported as unknown
If a position has no lots on record (history imported without the original buys, shares transferred in), its cost basis is not on record — never assumed to be zero. A fabricated $0 basis would produce a plausible-looking gain that is entirely wrong. The Portfolio status card names every holding whose basis is missing, so the gap is visible instead of silent.
Only FIFO, for now — honestly
Other lot methods (LIFO, specific identification) are modeled but not yet implemented; the control shows them disabled rather than pretending. Lot assignments you've relied on are never silently re-sorted.
Tax reporting (Pro)
Pro produces realized capital gains one line per closed lot, long-term and short-term separated as Form 8949 requires, with retirement accounts excluded from taxable gains. RockSolid Money is not tax software — it produces figures that reconcile, for you or your accountant.
Still need help?
If you're still stuck, contact us or email support@rockriverresearch.com — you will reach the people who build RockSolid Money.