After the Soviet invasion of Czechoslovakia in 1968, he defected to America, settled in San Francisco, and found employment in the management science department of Wells Fargo Bank in January 1969.
[2] In 1970, Wells Fargo sponsored a conference that included Fischer Black and Myron Scholes, who had just begun thinking seriously about the problem of valuing stock options.
Even their preliminary thoughts at the 1970 conference excited Vašíček, who soon made related issues his own life's work.
Vašíček's own breakthrough paper, "An equilibrium characterization of the term structure" [3] describing the dynamics of the yield curve, appeared in the Journal of Financial Economics in 1977.
Peter Carr, Head of Quantitative Financial Research at Bloomberg LP, included Vašíček's paper Probability of Loss on Loan Portfolio in the book Derivatives Pricing: The Classic Collection, which was marketed as a selection of 19 most influential papers on quantitative finance.