The total amortizes the signing bonus over four years. It’s the only reasonable way to compare packages, as some companies went heavier on signing and lighter on stock or vice-versa. Total for $100k base, $400k stock, $100k signing would be 100k (yearly) + 100k stock (yearly) + 25k signing (split over the four years) = 225k. Obviously it doesn’t work out that way in practice because you get signing upfront, but it’s a better comparison metric, imo.