Assuming this is not a 401k or regular IRA ...
You are taxed in one of three ways on your brokerage account
1) Any interest you receive (e.g., bonds) is taxed just like your income. This is like a bank savings account. Taxed in the year you earn the interest.
2) Any dividends you receive are taxed at a preferred dividend rate (can be complex in the US, there are amounts that based on your income level, may not be subject to tax, etc). Taxed in the year you RECEIVE the dividend
3) Taxed on the capitals gains x 50% at your marginal income rate. for example, let's say your $12k investment grew by $2k. You would have 50% x $2k = $1k at your top marginal income tax rate. Taxed in the year that you SELL.
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