The Twitter account Hidden Cash said money would be left in Central Park and Brooklyn's Prospect Park on Saturday.
The same Twitter account directed people last week to envelopes with $50 and $100 inside them in San Francisco and 36 cash-filled Angry Birds orbs in Hermosa Beach, California.
Bay Area real estate investor Jason Buzi went public as Hidden Cash in a CNN interview.
New Yorkers are finding the money and tweeting photos of themselves with their finds.
Hidden Cash retweets the smiling photos.
The New York envelopes each contain a $50 bill and a silver half-dollar.
Hidden Cash tweeted that the next giveaway is Sunday in Chicago.