Square 1 Financial has not yet said how many shares it will offer for its planned initial public offering nor has it given a price range for the stock but the company does say it will direct the vast majority of IPO proceeds to its profitable bank.

In an updated SEC filing, Square 1 Financial, the holding company for Square 1 Bank, said it expects to downstream roughly 90 percent of net proceeds of the IPO offering to the bank subsidiary.

Durham-based Square 1 publicly disclosed its intent to go public on Jan. 7, describing in securities filings plans to raise up to $58 million by selling stock to the public. Square 1 said it intends to use net proceeds from the offering to support long term growth by enhancing the amount of capital the bank has in light of the comprehensive banking reform measures referred to as Basel III. The company plans to trade on the Nasdaq exchange under the stock symbol “SQBK.”

Square 1, which launched in 2005, has steadily increased its profit in recent years. In 2011, net income was $5.3 million; it was $14.4 million in 2012 and $15.4 million through the first three quarters of 2013. The bank has not yet reported full fourth quarter financial results but it does have financial data for October and November. Net income was $4.0 million for the two months ending Nov. 30, a 122 percent increase compared with the same two months in 2012.

“During the two months ended November 30, 2013, we continued to experience growth due to our ongoing strategy of deepening our market penetration and gaining traction from our recent hiring of key people in the most active entrepreneurial markets and industries,” Square 1 said in its filing.

“Our banking teams continue to drive growth in our loan portfolio, deposits and fee income areas as well as in our off-balance sheet products. In particular, our total client funds, which consist of on-balance sheet deposits and off-balance sheet managed funds, increased 14.4% and 28.9%, respectively, during the two months ended November 30, 2013, reflecting continued growth from our existing clients as well as from new clients.”

For the 11 months ending Nov. 30, Square 1 reported $19.3 million in net income, a 54.3 percent increase over the comparable 11 month period in 2012. Square 1 reported $2.36 billion in assets through Nov. 30, along with $158.0 million in cash and cash equivalents. For comparison, at the end of 2012 the bank had $1.8 billion in assets and $55.2 million in cash and cash equivalents.

Earlier this month, Square 1 expanded its range of offerings in a deal for a financial services firm based in Silicon Valley.