Don't Buy Oak Street Health (OSH) Before Checking Its Margins!

Shares of Mid-cap Medical Care Facility company Oak Street Health were up 1.9% during today's afternoon session, as the S&P 500 posted a -0.8% change. Today's upwards movement shows that investor interest in OSH stock is strong -- but how closely have they studied the company's margins?

While Oak Street Health's gross margins for the last year are positive, we are concerned that the company's operating margins are in the red. Gross margins take into account only the cost of revenue, or variable costs -- meaning the cost directly associated with producing the products or providing the service offered by the company.

Operating margins, on the other hand, take into account the company's overhead as well. Overhead, also called fixed costs, includes the company's rent, salaries for personnel not included in cost of revenue, equipment and supplies, amortization, and depreciation. Operating margins tell you about how efficiently Oak Street Health is run, and gross margins tell you how profitable its product line is.

Since Oak Street Health's cost of revenue is growing at an average 117.1% per year, while its total revenues have a 65.3% growth rate, the only explanation for the widening margins is that the company is increasing its prices. Since prices cannot be increased indefinitely, Oak Street Health's gross margin growth will eventually slow unless it can get its cost of revenue under control.

The table above tells us that, on average, Oak Street Health has not been profitable over the last four years, which should be a warning sign to prospective investors. Indeed, the company's operating margins are sinking at rate of -9.5%