ZMH is an incredible earnings company (along with BMET and SYK) and these were downgraded on valuation, with which I concur. The p/e ratio for eBAY is currently 105 and that of ZMH is 35 (enough for a healthy correction). I would trade ZMH like I traded TARO and TEVA and look more for 'buying the swing high' after the first dip. Its a great question though because on the surface (the charts) the stocks might seem identical, but I'm looking more towards the FUTURE and not the past when EBAY could apparently do no wrong.
January 29, ZMH came out with an earnings report that moved the stock from 39 straight to 50, even as EBAY did similarly, it was a psychological advantage because I did hold ZMH for much of the rise, but I never got into EBAY on the long side. Can't see a company that is the world leader for orthopaedic reconstructive implants which is important for an aging community compared with EBAY. I've been wrong before, but we have to have some 'strategies' that work for us.