In a cash account, an investor must pay for the purchase of a security before selling it.  If an investor buys and sells a security before paying for it, the investor is “freeriding” which is not permitted under the Federal Reserve Board’s Regulation T and may require the investor’s broker to “freeze” the investor’s cash account for 90 days.  During this 90-day period, an investor may still purchase securities with the cash account, but the investor must fully pay for any purchase on the date of the trade. 

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