Investors are unfazed about the government shutdown. Here's how stocks have fared during previous closures.

Stocks closed at record highs Wednesday despite a U.S. government shutdown expected to idle hundreds of thousands of workers and hobble federal agencies charged with dispensing a range of critical services. So why do investors seem unfazed?

Although shutdowns have serious, real-world consequences for millions of Americans, data shows they tend to have a modest impact on financial markets and the broader economy, especially if the closure is brief.

"Most of the economic activity is delayed and usually gets made up shortly after a shutdown ends," Sameer Samana, senior global market strategist at Wells Fargo Investment Institute, told CBS News. "So I can't imagine this will be anything terribly disruptive for the equity markets."

Over the previous 22 shutdowns the U.S. has seen since