[nsp]

37.5 basis points is 0.375%, the percent of his stock that had not yet vested and this is returned to the stock option pool to be given out to future hires

[loumf]

Bob has 1%, so it's 37.5% of his stock that is not vested after 2.5 years. (0.375% of the company's stock)

It's 25%/year with 4 year vesting (so 25 + 12.5 for the 1.5 years left)