A Capital Gain Appears When a Higher Value Becomes a Sale
Two years after you bought in at $8,000, the position on your screen reads $11,000. That extra $3,000 is only a number — until the day you sell, when it becomes a capital gain.
A capital gain is the profit from selling a capital asset — stock, fund shares, crypto, real estate — for more than your adjusted cost basis. Basis is roughly what you paid, adjusted for things like commissions, reinvested distributions, and stock splits.
Realized vs. unrealized
Until you sell, the gain is unrealized — paper profit that can grow, shrink, or vanish. Selling makes it realized, and realized gains are generally what land on a tax return.
The distinction cuts both ways: a position that's fallen from its peak but still sits above your basis is a gain if sold today. The market grades against its own highs; the IRS grades against your basis.
The math, kept honest
Sell for $11,000 what you bought for $8,000 and your capital gain is $3,000. The other $8,000 of the sale isn't income — it's your own basis coming back to you.
That's why proceeds and profit shouldn't be confused. A $50,000 sale can contain a $2,000 gain, no gain at all, or a capital loss.
Why the holding period matters
Under current federal rules, hold an asset more than one year before selling and the gain is long-term, taxed at preferential rates. Sell at one year or less and it's short-term, taxed like ordinary wages.
The rate schedule, the netting rules, and the paperwork all belong to the capital gains tax. Inside IRAs and 401(k)s, sales don't create current taxable gains — those accounts run on their own timetable.
What a gain doesn't tell you
One profitable sale says little by itself. A $3,000 gain earned over ten years on a large position may badly trail inflation or a benchmark — the annualized rate of return tells you whether the gain was actually good.
Taxes and fees only take their cut when you act. Trading in and out realizes gains early and often; patience defers the bill.
For the federal rules straight from the source, see the IRS's Topic 409 on capital gains and losses.
Log your purchase price and date the day you buy — future you needs that basis the day you sell.