With KKR (KKR) up 41% in the last twelve months, the shares of Blackstone (BX) are now trading at their lowest relative valuation to the former, which Morgan Stanley analyst Michael Cyprys said he views as unjustified. He attributes a mix of C-corp conversion, CRSP index inclusion, and strong asset gathering and fee growth at KKR for the strength, but also believes Blackstone's upcoming investor day on September 21 could be a catalyst to fix the "valuation disconnect." While he doesn't expect a C-corp conversion announcement in the near-term, Cyprys wouldn't be surprised to see Blackstone follow KKR's lead and shift toward a cash earnings approach from reporting on a more volatile mark to market basis, he tells investors. The analyst, who could see a $50 valuation for Blackstone if the stock re-rates to its historical premium to KKR, keeps an Overweight rating and $42 price target on Blackstone shares.