While investors have turned quite bullish after the European Central Bank said it would initiate a bond-buying program to help stabilize Europe’s financial system, Vanguard founder Jack Bogle says they shouldn’t overreact.

“I think the market generally takes these things far too seriously,” Bogle told CNBC. “When the ECB chairman says he will do ‘whatever it takes’ it’s like me saying I’ll do whatever it takes to beat Tiger Woods the next time we’re out on the golf course.”

Bogle says investors shouldn’t overreact to short-term market fluctuations, and should think about whether there is anything new that would impact their long-term plans.

Over the long term, Bogle still expects stocks to post about 7% nominal returns. That’s less than historical averages, but still much greater than the 2% to 3% return he expects on bonds.