If you have recently or not recently bought stocks or a mutual fund and they have gone down
you can sell them at a loss and claim a net capital loss of up to $3,000;
but you might have purchased these securities for the long term and you want to hold them
you are subject to the "wash rule" which means you cannot rebuy the same securities for 30 days after you sell them or for 30 days before you sell.
However, you could surely find a very similar stock of fund that you could immediately buy
Or you could take a chance for 30 days where very often an equity movement will be marginal or it could go against you or could favor you if you do this
Or you could double up for 30 days just before the selloff so as not to miss an upward movement - although you would risk a downward movement if you do this
A legitimate additional deduction of $3,000 which this play can generate will benefit the average earner by about $1,000 net in cash
This is not applicable to an IRA - only to a regular account