Privately held, Boca Raton-based 1st United Bancorp has raised $11.7 million from its shareholders to fund further expansion. CEO Rudy Schupp says capital is king again and that the money wasn’t required for the growth, but its arrival creates more opportunities. The bank recently bought Citrus Bank of Vero Beach and Equitable Financial Group of Fort Lauderdale. It can also shore up its balance sheet now. The company acknowledged in its registration statement that it’s doing business in the heart of a volatile region, and told shareholders that its loan portfolio is heavily concentrated in mortgage loans secured by properties in South Florida.