Things were going very well for Goldman Sachs, for the J Aron division, and for me at the firm. At the end of 1990, John Weinberg retired, and Bob Rubin and Steve Friedman became co-senior partners and co-chairs of the management committee. That was all as anticipated. Less expected was when Rubin left two years later to become chair of President Clinton’s newly created National Economic Council. Part of the idea of having co-heads was to create a balance between trading and investment banking. When Rubin left after such a short time in the job, there was no longer someone at the top of the firm with deep experience in trading. Steve Friedman chose not to elevate a co-head, leaving an imbalance that would have consequences.

Under Mark Winkelman’s guidance, J Aron had moved from arbitrage and risk avoidance to being a risk- based trading firm that was applying technology and quantitative analysis to foreign exchange, energy, metals, and fixed income. Aron was simultaneously becoming more of a client-focused business and more like a hedge fund.

The two went hand in hand. Being at the centre of so much trading flow – and having top analysts like Morrison and Davies – gave us...

Read more