If you have an IRA, you can use IRA funds to buy, sell, and buy back shares in your retirement account as often as you want in a day. Using an IRA for trading can help you postpone paying taxes on profits earned from selling stocks and eliminates the need to file taxes. The simplified selling rule prohibits capital losses if the same security is bought again within 30 days of its sale. This is bad for unprotected investments, but it has no consequences for traders who buy and sell in an IRA, since no capital losses are reported in an IRA.
However, you can't circumvent the fraudulent sale rule by selling shares in your regular account at a loss and buying them back within 30 days in your IRA account. The IRS calls this a fraudulent sale and will dismiss your claim for loss in your regular account. Despite regulations, IRAs are quite similar to regular investment accounts in terms of the investments allowed in the account. If you can buy or sell stocks in a regular account, you can also buy or sell them in your IRA.
On the other side of the coin are tax losses. When you sell stocks at a loss in a taxable account, you can deduct losses from your profits and even from your regular income up to a limit. If you sell a stock within an IRA at a loss, you won't get that benefit. You cannot short sell shares in an IRA, since you must use it as collateral for the loan, which is a prohibited transaction.