NEW YORK, Aug. 26 -- The Dow Jones Industrial Average is meant to be a portrait of American industry. In the latest session on Wall Street it was mostly a portrait of one trading floor.

The index closed at 53,577.40 on Tuesday, the most recent completed trading day, up 160.24 points or 0.30 per cent. By Eastern Herald's calculation Goldman Sachs supplied about 139 of those points by itself, roughly 87 per cent of the day's gain. Three sessions earlier the same bank delivered about 44 per cent of a 518-point rally.

Two sessions do not make a pattern. What makes this one is the reason, and the reason sits in Goldman's own quarterly filing: market-making revenue rose 61 per cent year on year. Goldman is paid more when markets become harder...