A couple of years ago, wearing a suit and tie marked you as a stick-in-the-mud. It might mean you were caught in the past and didn't get the new economy.
And if there was one thing bankers didn't want to be suspected of during the bull market, it was not understanding the new economy. Out went the suit, in came business casual.
Most investment banks relaxed dress codes. Most still allow employees to dress down, insisting on suits when they go to meet clients. But the cold winds of a slowdown are blowing through the industry, bringing sartorial change with them.
Lehman Brothers was among the first to go back to smart attire in February. Deutsche has followed. Management sent out a memo stating that over the past 18 months there had been a "significant shift" in clients' views on appropriate dress.
The bank became concerned that staff were taking things too far. The memo proscribes jeans, sports wear and trainers, shorts, crop tops, outsize clothing and "clubbing attire". The restrictions apply throughout the week, except for Fridays.
This looks like an attempt to distance the bank from the imploded dot com culture that dressing down has come to symbolize.