I've been tracking the number of new cases that are reported every day in the U.S. This metric will likely provide the first indications that the curve has peaked. The growth rate has seemed to slow over the past few days, but it's still increasing.
Mar. 16th - 983
Mar. 17th - 1,748
Mar. 18th - 2,848
Mar. 19th - 4,530
Mar. 20th - 5,594
Mar. 21st - 4,824
Mar. 22nd - 9,339
Mar. 23rd - 10,168
Mar. 24th - 11,075
Mar. 25th - 10,796 (Current count as of 6 pm)