Vaccines are better than you think — plus Robinhood, schools, and hurricanes

A Saturday fast takes roundup

Happy Saturday — here’s some quick takes.

Vaccines are really good

When you read in the press that a vaccine is 90 percent effective vs another one that’s only 70 percent effective, do you know what that means? It turns out that what everyone is measuring in their Covid trials is the share of people in the control group who develop symptoms vs the share …