Portfolio Tax Lot Review
Last verified: 2026-07-04 PDT
A portfolio tax lot review is the habit of checking which shares a taxable account may sell before the trade is placed. Two positions can have the same ticker and the same dollar value while carrying very different cost basis, holding period, unrealized gain or loss, and recordkeeping consequences.
This page is educational workflow, not tax guidance. Source-sensitive tax framing was checked against IRS Publication 550 and IRS Topic No. 409 on 2026-07-04 PDT. Rules can change, and personal tax questions belong with official IRS materials or a qualified tax professional.
Quick definition
A tax lot is a record of a specific purchase: date, quantity, price, fees if applicable, cost basis, and later sale information. A portfolio tax lot review compares those lots before a taxable-account sale, rebalance, transfer, or harvest decision.
The simple tax lot worksheet
Create one row per lot, not one row per ticker:
| Field | Why it matters |
|---|---|
| Ticker and account | Keeps taxable, retirement, and other accounts separate |
| Purchase date | Helps identify holding period and review timing |
| Quantity | Shows partial-lot sale choices |
| Cost basis | Anchors unrealized gain or loss math |
| Current value | Shows exposure now, not just original purchase |
| Unrealized gain or loss | Helps compare lots before a user-directed sale |
| Notes | Records why a lot is being reviewed |
The goal is not to game every penny. The goal is to avoid clicking sell without knowing what the account is actually disposing of.
Example: same ticker, different lot
Imagine an investor owns two lots of the same ETF:
- ▸Lot A: 10 shares bought at $80, now worth $100.
- ▸Lot B: 10 shares bought at $115, now worth $100.
Both lots are the same ticker. Lot A has an unrealized gain of $20 per share. Lot B has an unrealized loss of $15 per share. Selling “the ETF” is not specific enough. The tax lot review asks which lot, how many shares, why this action, and what record needs to be saved after the trade.
What to check before a taxable-account sale
Start with the portfolio reason. Is this a rebalance, a cash need, a risk reduction, a tax-loss harvesting review, or a cleanup trade? Then check the lot-level details: basis, unrealized result, holding period, recent purchases, planned repurchases, and whether the sale could interact with wash-sale rules.
A good review also asks whether the portfolio can reach the same risk goal with a smaller sale, a new contribution, a different account, or a scheduled rebalance later. The right answer is user-specific, but the checklist keeps the trade from being vague.
Common mistakes
The first mistake is treating a ticker as one blob. The second is reviewing taxes only after the order fills. The third is ignoring documentation: confirmations, basis reports, 1099-B forms, transfer history, dividend reinvestment lots, and notes about why the trade happened. The fourth is assuming tax software can reconstruct intent that was never recorded.
Bucko workflow
Use Bucko as an educational research and journaling workspace. Save the lot review, write the reason for the user-directed action, attach assumptions, and mark the review date. If automation or alerts are involved, keep them user-configured with guardrails, daily caps, and a kill switch.
Bucko workflow checklist
- ▸Separate taxable-account decisions from retirement-account decisions.
- ▸Review lots before placing a sale, not after.
- ▸Save basis, dates, quantities, and the reason for action.
- ▸Check official IRS materials or a qualified tax professional for personal tax questions.
- ▸Review the outcome after statements and tax forms arrive.