Rockefeller's wealth, while staggering for 1913, was constrained by the limitations of oil refining margins and early-20th-century capital structures. Standard Oil generated ~$90M annually at peak, but Rockefeller's personal stake was diluted across shareholders and reinvestment obligations. The antitrust breakup in 1911 actually fragmented his wealth—he held pieces of multiple companies rather than one concentrated goldmine. His $340M represented a snapshot frozen in time before exponential growth was possible; oil refining was a mature commodity business by then.

Boeing, conversely, built during aviation's explosive growth phase when the industry was literally being invented. His 1929 peak came right before the Depression, but he'd already established Boeing as the dominant defense and commercial aircraft supplier—a business with vastly superior unit economics and margins compared to oil refining. Aircraft manufacturing commanded premium pricing, government contracts provided recurring revenue streams, and the industry's 50-year growth runway hadn't even begun. Boeing didn't just own a refinery; he owned the foundational IP and production capability for an entirely new transportation mode.

The real differentiator: Rockefeller's wealth came from controlling supply of a commodity that already existed (oil). Boeing's came from *creating demand* for something that didn't—and then maintaining monopolistic control over manufacturing it. When you're the only credible builder of commercial aircraft during the aviation boom, your margins compound differently than when you're one of several oil refiners. Boeing's $150M in 1929 had higher growth potential embedded in it; Rockefeller's $340M in 1913 was closer to a ceiling.