NEW YORK — Rising commodities prices and stirrings of corporate takeovers are making investors more optimistic about the economy.

Stocks rose for the third straight day yesterday as gold topped $1,000 an ounce for the first time since February and oil jumped more than $3 a barrel. The rising prices helped lift material and energy stocks. The gains in commodities came as the dollar fell and investors looked for more ways to profit from an improving economy.

Talk of a revival in corporate dealmaking also boosted the mood on Wall Street. A takeover bid from Kraft Foods Inc. for rival Cadbury PLC — even though Cadbury rejected it — combined with a big phone deal in England lifted hopes that takeover activity could be picking up.