As CEO, O'Neal attempted to get rid of the 'Mother Merrill' culture of job security, arguing that it promoted cronyism instead of merit. He also wanted to transform Merrill into a trading powerhouse, and to beat Goldman Sachs at its own game. After the departure of Chris Ricciardi, O'Neal hired Osman Semerci on the advice of fixed-income head Dow Kim and chief administrative officer Ahmass Fakahany. Semerci continued the push into the subprime mortgage-backed CDO market, and grew the firm's position from $5-$6 billion worth of exposure to $55 billion in under one year, while firing respected trader Jeff Kronthal and demoting risk manager John Breit, both of whom had warned against too much exposure to CDOs. Merrill was one of the top CDO underwriters of the boom era, a plan that initially brought huge bonuses to Merrill until the markets turned. According to the then-president of Merrill, Greg Fleming, the dismissal of Kronthal in July 2006 was the day Merrill Lynch’s fate was sealed, otherwise the firm may have "avoided the subprime problems that would soon bring Wall Street to its knees. After that date, Merrill was doomed to make the same mistakes as its competitors."