$re = '/(?:NASDAQ|NYSE)[^\)]+/mi';
$str = '(NASDaq/abnjnxd:number1) ojsnxsjsxmjosx (nasDaq:number2) (NYSE:bhdnd) (Nasdaq:eres)';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php