Commonwealth Bank chief executive Matt Comyn could be in for a $40 million windfall as the country’s biggest lender’s share price soars.

The bank is one of the most expensive in the world, with shares hitting record highs this week after surging almost 50 per cent over the last 12 months and 75 per cent over two years, as major superannuation funds and global investors seek a safe haven in the local sharemarket’s largest stock.