Grant's wealth advantage stems from one critical difference: negotiating leverage and timing. While both men were early adopters of profit participation deals, Grant secured these arrangements during Hollywood's most lucrative period (1940s-1950s) when studio profits were astronomical and he had maximum bargaining power as a box office titan. Stewart, though beloved, positioned himself as the reliable everyman—which made him bankable but not irreplaceable. Grant's selectivity meant he turned down projects, forcing studios to sweeten deals; Stewart's accessibility meant he had less leverage to demand backend percentages on every project.

The deal structures themselves reveal the nuance. Grant's partnerships were broader and deeper—he didn't just take a piece of individual films, he negotiated overall deal structures with studios that gave him percentage stakes across multiple productions and sometimes even distribution rights. Stewart's genius was applying the same profit-sharing concept, but more conservatively. His deals were film-by-film rather than portfolio-wide, which meant he captured upside from his biggest hits (Vertigo, It's a Wonderful Life) but missed the compounding wealth-building that comes from systematic backend arrangements across a full slate.

Perhaps most importantly, Grant was ruthlessly pragmatic about reinvestment and business operations, while Stewart remained primarily a performer-turned-investor rather than a true entrepreneur. Grant actively managed his investments, negotiated with accountants and lawyers to optimize structures, and treated wealth accumulation as a business discipline. Stewart, by contrast, was a decorated WWII pilot first and a businessman second—his humility about money actually cost him millions in optimization opportunities. Two great actors, two different relationships with ambition.