How do I find a stock's cost basis?

If you know when the stock was purchased, here are some tips:

• Sign in to your brokerage account
  • Although your broker may not include your basis on your 1099-B, it doesn't necessarily mean they don't have it.
  • If your current broker was the selling agent, there's usually a wealth of documentation available in your online brokerage account that can help, such as detailed reports on each sale.
• Look at previous broker statements
  • Review your records for the trade confirmation when you bought the shares. (It's always a good idea to save these for tax purposes.)
  • If you purchased the stock at different times or haven't sold all the shares at once, you may have more than one trade confirmation statement.
• Contact your brokerage firm
  • Your broker should have a record of the purchase, if you bought the stock from them.
  • If not, they might still be able and willing to look up the historical stock price for you.
• Go online for historical stock prices
  • For example, view the historical section at Marketwatch or Nasdaq. It's generally acceptable to take the lowest and highest price from a given day and average them to arrive at a cost. It's also acceptable to use the closing price on the day of purchase.
  • These free services may not include events that affect basis, such as reinvested dividends, spin-offs, and stock splits.
• Go directly to the source
  • Many companies have an investor relations section on their website that contains historical stock data. You can also call the company's shareholder services department for help.
  • For shares purchased more than 10 years ago, go to a public library or law school library and look for back issues of newspapers, such as USA Today, to find the high and low price on the date of purchase.