SEC Chief Gary Gensler Says the Stock Market Needs an Update

The plumbing of the U.S. stock market, like actual plumbing, tends to operate quietly in the background.

In January, as if a wall had been ripped open, the market’s tangled and decades-old pipes were suddenly exposed to millions of retail investors who had given little thought to them before. They had piled into stocks like GameStop (ticker: GME).

Then,…