AMONG HOUSEHOLDS a record 44 per cent now own stocks. Yet they've been taking some money out. Last year, individuals sold a net $500bn of the equities they hold directly. Net purchases by mutual funds fell 14 per cent. So why is the Dow still going up? Partly, it's the result of a net decline in the supply of stocks. Things like mergers and buybacks shrank the market by $178bn last year. Speculation is helping, too. As a percentage of personal income, money borrowed from brokers to buy stock has never been so high. And you can't rule out the DowGen's bull. It's their special mark.