[laurencerowe]

There is no limit to the amount of capital losses carried over (i.e. harvested) year to year. These must first be applied against any capital gains (no limit AFAIK.) The $3000 limit applies to the annual amount of capital losses that may be written off against other income.

Example, in year 1 you have a $15,000 net capital loss. You write off the maximum $3,000 of this against your other income, carrying over a $12,000 capital loss. In year 2 you have a $10,000 net capital gain, this is offset against your carried over loss leaving $2,000 to write off against your income.