The current institutional shareholding score of Westamerica Bancorp is 10.00, ranking 1 out of 398 in the Banking Services industry. The latest institutional shareholding proportion is 96.55%, representing a quarter-over-quarter increase of 18.26%. The largest institutional shareholder is James Simons, holding a total of 0.00 shares, representing 0.65% of shares outstanding, with 0.15% increase in holdings.