Googled but couldn't find anything on the dozen so posters bearing tales of Wall Street suicides. Mark Madoff is the only recent one I remember. I googled the other names in the other four pictured here until I got one hit. The NY Times ran a report (not this one) on Ignacio Martinez's suicide in its November 13, 1894, paper. The Times had the better head: "The Stock Exchange Broker Kills Himself with Illuminating Gas."
Illumination can be so deadly.
The posters are part of a crowdsourced wheat-past wall that wraps around the southeast corner of 10th Street and 4th Ave.
I didn't check when I was there to see if they were all Wall Street suicides or not.