If you sold stock or mutual fund shares in 1999, you need to know your cost basis to figure out your capital gain or loss. Ask the mutual fund company or the transfer agent servicing a stock dividend reinvestment program for a history of your account activity. Check old tax returns for information about dividend payments. Reinvested dividends should be added to the cost basis for your investment because you already paid taxes on them. Look up old share prices.
Many libraries have old newspapers on microfilm, and some historical information is on the Internet.
Check with a company's investor relations department for a history of stock splits and spinoffs you can use to adjust your cost. Ask a tax preparer for help. A preparer may have gathered some of the information you need from other clients who owned the same stock. But if extensive research is required, expect to be billed for it. All rights reserved.