By Jonathan Weil
In a feat that would seem to defy the odds, Goldman Sachs, JPMorgan Chase and Bank of America this week each said its trading desk made money every day of the first quarter. Goldman said its daily net trading revenue topped $100 million 35 times last quarter out of 63 trading days. JPMorgan and Bank of America disclosed similar eye-popping stats. Citigroup, too, recorded a profit on each trading day, Bloomberg News reported, citing unnamed people who knew the results.
The intrigue is high. If a too-big-to-fail bank’s traders were able to make money every day of a quarter, were they really trading in any normal sense of the word? Or would vacuuming be a more accurate term? What kinds of risks do such incredible profits entail, for the banks and the rest of us taxpayers? And are results such as these too good to be true?
There seems to be no satisfying way to answer those questions, or even the more basic inquiry: How exactly do these banks’ trading divisions make money? Reading the companies’ impenetrable financial reports is of little help. However they did it, the data suggest it was as easy last quarter as hitting the side of a barn with a baseball from three feet away.
This isn’t the way “trading” works in the real world. A simple exercise in measuring probabilities is instructive here.