A hundred billion is the new hundred million. State Street’s SPYM fund surpassed $100 billion in assets last week, making it the fastest to grow from$50 billion to $100 billion, taking just 283 trading days, according to State Street. The ETF is the latest entrant to the core S&P 500 cast and represents the firm’s efforts to access growing retail markets via low fees; SPYM’s is just two basis points. But it may be the last core S&P 500 product breakthrough for a while because of all the funds already tra ...