One profitable company is not the same as another, and investors who ignore that distinction often pay the price when business conditions shift.

McKesson (NYSE: MCK), with roots dating back to 1833, is one of America’s oldest continuously operating businesses, distributing pharmaceuticals, medical supplies, and providing technology solutions to pharmacies, hospitals, and healthcare providers.

McKesson’s annual sales growth of 14.5% over the last two years is well above market averages, signaling that its offerings and unique value proposition continue to resonate strongly with customers.

The company’s massive revenue base of $411 billion in a highly regulated sector makes it exceptionally difficult to replace, granting it meaningful negotiating power with suppliers and clients alike.

McKesson’s annual earnings per share growth of 15.3% has outpaced its revenue gains over the last five years, a trend amplified by consistent share repurchase activity that has compounded shareholder returns.

With a trailing 12-month GAAP operating margin of 1.6% and shares trading at $930.67, or 19.5x forward P/E, McKesson presents a compelling case as a long-term hold in the healthcare distribution space.

On the other side of the ledger, Chewy (NYSE: CHWY), the online pet food and supplies retailer founded by Ryan Cohen, is showing several signs that its growth story may be running out of steam.

Chewy’s annual revenue growth of 6.5% over the last three years fell below acceptable benchmarks for the consumer internet sector, and projected sales growth of just 7% for the next 12 months suggests demand is softening further.

A gross margin of just 29.7% reflects high servicing costs that limit Chewy’s ability to convert revenue into meaningful profit, with shares currently implying a valuation of 8.2x forward EV/EBITDA at a price of $18.87.

Wendy’s (NASDAQ: WEN), the fast-food chain founded by Dave Thomas in 1969, faces its own set of structural headwinds that make its current profitability difficult to sustain over the medium term.

Poor same-store sales performance over the past two years indicates Wendy’s is struggling to attract new diners, while costs have risen faster than revenue, causing its operating margin to fall by 3.4 percentage points.

An 8x net-debt-to-EBITDA ratio signals that Wendy’s is significantly overleveraged, raising the probability of shareholder dilution if business conditions deteriorate unexpectedly, with shares trading at just $6.22 or 12.7x forward P/E.

The broader takeaway for investors is that profitability alone is not a sufficient reason to hold a stock, particularly when underlying growth, margin trends, and balance sheet strength tell a more cautious story.