[GUIDE] Capital Gains Taxes for Redditors: Stocks, Tips and Not Getting Wrecked
TL;DR
- You’re generally taxed on profit (gain), not the whole sale: Proceeds − Cost basis (± fees).
- Holding period matters: short-term (≤ 1 yr) vs long-term (> 1 yr).
- For high-volume traders, TurboTax does the heavy lifting: automatically importing up to 10,000 stock and 20,000 crypto transactions and pulling tax forms directly from your financial institutions — no manual work required.
- Get your transaction history + cost basis organized now.
Share your situation and get help from a TurboTax expert.
1) ELI5: Capital Gains
A capital gain happens when you sell something (e.g. stock) for more than you paid. A loss is selling for less.
Example: buy at $100, sell at $160 → gain $60 (not $160).
What is the Capital Gains Tax? - TurboTax Tax Tip Video
2) “Do I owe tax on the whole sale?”
Usually no, it’s typically about the profit. What matters is your cost basis (what you paid) and what you received when you sold.
3) What counts as a taxable event?
Stocks
- Sell shares → gain/loss
- Dividends/interest can also be taxable (separate from capital gains)
4) How to calculate your gain
Core formula:
Capital Gain (or Loss) = Proceeds − Cost basis − fees
Cost basis is where people get cooked, especially with multiple buys.
Common tracking methods you’ll see:
- FIFO (First In, First Out)
- Specific ID (pick exact lots/units—requires good records and correct settings)
Example:
Buy 1 RDDT for $100. Sell at $200.
Gain = $200 − $100 = $100 (before fees).
With TurboTax Investors can upload forms from providers like Fidelity or E*Trade and the AI assistant can handle cost basis adjustments reducing taxable income
Short-term vs long-term overview
5) Losses can save you money (seriously)
Capital losses can offset capital gains. If you’re net down, you may be able to deduct up to $3,000 against ordinary income (and potentially carry the rest forward). This is why you’ll hear “tax-loss harvesting.”
6) What to pull TODAY
If you only do a few things before filing:
- Download your brokerage 1099 and/or gain/loss reports
- Have TurboTax automatically ingest your forms and information directly from brokerage firms and crypto platforms to get rid of all the manual entry
- Confirm cost basis method (FIFO vs Specific ID) where applicable
- Keep receipts for oddities (fees, transfers, missing lots)
If you’re high-volume, multi-exchange, or dealing with edge cases, it may be worth looping in help rather than doing guess work. A TurboTax expert can walk you through your specific situation.
Open Q&A: drop your scenario
Everyone’s welcome to share tips and upvote good DD. Comment your questions, such as:
- “What if I sell my position that is a mix of short and long term holdings?”
- “My broker shows the cost basis… am I done?”
Quick links:
Posted Apr 9, 2026, 9:23 PM UTC · locked