David Seetapun

David Seetapun is an English logician and former investment banker.

During the fall of 1990, David Seetapun was said to have "'used a very interesting 0'"- priority argument to prove that every r.e. degree 0 < a < 0' is locally noncappable, namely (35) (Va) o < a < o' (3c) a < c (Vb) b < c[anb = 0 => b = 0". Seetapun received a PhD in logics from Cambridge in 1991, under Robert I. Soare, the topic was "Contributions to recursion theory". He went on to a post-doctoral position at Berkeley where in 1995 he published an influential article with his post-doctoral adviser Theodore Slaman on the topic of Ramsey's theorem. He also proposed the so called "Seetapun Enigma", a mathematical puzzle that was not solved until 2010 by Chinese undergraduate student Liu Lu.

After graduating he took a job for Credit Suisse, but was offered a job by Goldman Sachs. Seetapun made a reputation for himself managing a trading venture with mathematical models, and has been cited as "Goldman's top London proprietary options trader". He left Goldman in March 1998, when he was rehired by Credit Suisse. In 1998 his models started to fail causing a loss of some 100 million dollars of his own funds as well as for the firm. He was dismissed and went first to Las Vegas to live as a gambler and later to Florida to work in the swordfish fishing fleet.