As the second largest ETF provider on the planet, why wouldn't Vanguard's notice have been mostly to do with ETF inflows? This time last year, the world's third largest ETF provider, State Street, became "Subs" for NAN with 5.31% on September 25th, and then dropped below 5% the very next day. Perhaps Vanguard have some biotech ETF or healthcare ETF that NAN is in that became more popular. I mostly ignore notices from BlackRock, Vanguard and State Street, as I regard those three as passive money managers through their ETFs. In my experience those three pop in and out as "Subs" with heaps of smaller and mid-sized companies on a regular basis and it generally means very little, IMO.