According to @QCompounding, Mark Miller—dubbed by some investors the "Charlie Munger of Software"—holds roughly $700 million of Constellation Software (TSX:CSU) stock and bought additional shares in the open market after Mark Leonard stepped down, indicating he views the stock as a buy (source: @QCompounding). For trading context, insider open‑market purchases are historically associated with positive abnormal returns, which many traders treat as a bullish signal (source: Lakonishok and Lee, 2001; Seyhun, 1986).