When I started on Wall Street most things were still traded this way. I was trading Emerging Market Bonds over the phone and never used these signals except across a crowded loud room, and even then I mostly got them wrong. I usually had to resort to a phone call.

However, over time, some things became part of my body language vocabulary. I’ve confused girlfriends and friends who never used these signals by using them instead of talking sometimes.

Here’s a link to a photo essay on some of these trading signals from the oil pit of the NYMEX.
http://www.nytimes.com/interactive/2008/04/07/opinion/20080407_TRADING_GRAPHIC.html