ADVICE FROM CEOs on Instagram: "Meet Bill Ackman — billionaire investor, hedge fund titan, and the embodiment of a Wall Street comeback. Once celebrated for his bold strategies, he took a massive gamble on Valeant Pharmaceuticals—and lost $4 billion. Panic swept through his investor base. His personal life unraveled; his 25-year marriage ended. His reputation? Nearly destroyed. In the aftermath, few thought he’d bounce back. Critics circled, headlines piled on, and the financial world doubted hi