Robert J. Birnbaum, Director at CBOE Holdings, Inc. (CBOE), bought 300 shares at $29.00 ($9K) on 2010-06-18, disclosed to the SEC on 2010-06-18.
Open-market purchase of $9k CBOE by Director. Below the thresholds we flag for high-conviction alerts (no C-suite role, rare reversal, cluster, or A-grade history).
Nothing distinguishes this filing.