Isaac Stein is Director at MAXYGEN INC (MAXY). They have made 3 open-market trades across 1 company since 2006, most recently 2016-06-21.
Unrated. We grade insiders only on stock they chose to buy on the open market. Grants, option exercises and vesting say nothing about timing, so they don't count — which is why someone can file often and still have no grade. It isn't a bad sign: unrated buys beat every graded tier below A.
1 open-market purchase totalling $103K since 2011, against 2 sales. Too few scored purchases to measure a record yet.
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.