Stock-based compensation is a real cost even though many investors treat it as a non-cash footnote. Mechanism: SBC dilutes existing shareholders. Excluding it from adjusted earnings makes profitability look better than the economic reality. Over time, heavy SBC can transfer significant ownership value away from shareholders even while the headline business grows. Market translation: A tech company reporting "adjusted" EPS well above GAAP EPS may be hiding 5-10% annual dilution that quietly eats into per-share value. Failure mode: The mistake is accepting adjusted earnings as the real story without adding back the dilution cost to your ownership math. Review question: Before sizing up, identify whether the edge comes from cash flow, volatility, timing or balance-sheet structure. That is the kind of small conceptual habit that compounds into better decisions over time.