Not saying it couldn't drop ( or jump) by $40 but how many of the others in the industry have their growth rate, prospects and monopoly?
Industry averages, like book value are largely meaning less over the short term for a company like ISRG. Will they return to the mean? perhaps over 8 10 or 12 years, but there is little reason for that to happen over the next 1 to 2. If all goes well they will have a similar PE, only on a higher E this time next year.