St. Louie Woman,
So dollar cost average in the market by buying the stock in small lots, say under $1,000 each buy. If the drop continues, you still have a low average, like in Ford or GM, and if you get too worried, you can stop buying and move to another stock, don't like 3M, switch to Rubbermaid or General Mills.
Regatdless, you've got to be reaDY TO SIT ON THE STOCK FOR AT LEAST 5 YEARS IN THIS MARKET.