Dirty jokes and NSFW GIFs. Snaps of unsuspecting colleagues on the trading floor. Screenshots of confidential client positions. All that — and, on occasion, even legally dubious information — is increasingly being trafficked over the new private lines of Wall Street: encrypted messaging services like WhatsApp and Signal. From traders to bankers and money managers, just about everyone in finance is embracing these apps as an easy, and virtually untraceable, way to circumvent compliance, get around the HR police and keep bosses in the dark.