Mirati Therapeutics's price surge today seems to be confirming the bullish analyst outlook on the stock. Ending the day at $95.85, MRTX has posted 11.3% gains, pushing the valuation of the stock even higher. Might the stock be overvalued, despite its buy rating?
The first step in determining whether a stock is overvalued is to check its price to book (P/B) ratio. This is perhaps the most basic measure of a company's valuation, which is its market value divided by its book value. Book value refers to the sum of all of the company's tangible assets minus its liabilities -- you can also think of it as the company's liquidation value.
Traditionally, value investors would look for companies with a ratio of less than 1 (meaning that the market value was smaller than the company's book value), but such opportunities are very rare these days. So we tend to look for company's whose valuations are less than their sector and market average. The P/B ratio for Mirati Therapeutics is 4.9, compared to its sector average of 4.07 and the S&P 500's average P/B of 2.95.
Modernly, the most common metric for valuing a company is its Price to Earnings (P/E) ratio. It's simply today's stock price of 95.85 divided by either its trailing or forward earnings, which for Mirati Therapeutics are $-11.96 and $-12.85 respectively. Based on these values, the company's trailing P/E ratio is -8.0 and its forward P/E ratio is -7.5. By way of comparison, the average P/E ratio of the Healthcare sector is 13.21 and the average P/E ratio of the S&P 500 is 15.97.
The problem with P/E ratios is that they don't take into account the growth of earnings. This means that a company with a higher than average P/E ratio may still be undervalued if it has extremely high projected earnings growth. Conversely, a company with a low P/E ratio may not present a good value proposition if its projected earnings are stagnant.
When we divide Mirati Therapeutics's P/E ratio by its projected 5 year earnings growth rate, we obtain its Price to Earnings Growth (PEG) ratio of 0.1. Since a PEG ratio between 0 and 1 may indicate that the company's valuation is proportionate to its growth potential, we see here that MRTX is actually fairly valued if we factor growth into the price to earnings calculus. One important caveat here is that PEG ratios are calculated on the basis of future earnings growth estimates, which may turn out to be wrong.
Indebted or mismanaged companies can't sustain shareholder value for long, even if they have strong earnings. For this reason, considering Mirati Therapeutics's ability to meet its debt obligations is also an important aspect of pinning down its valuation. By adding up its current assets, then subtracting its inventory and prepaid expenses, and then dividing the whole by its current liabilities, we obtain the company's Quick Ratio of 9.529. Since MRTX's quick ratio is higher than 1, its total liquid assets are sufficient to meets its current liabilities.
Lastly, we consider Mirati Therapeutics's free cash flow of $-398,595,000.00. This is the sum of all of its incoming and outgoing cash flows -- including those that are unrelated to its core business, such as rent, legal costs, income from investments, debt payments, etc. A negative cash flow for a single quarter is not a particularly serious issue for a company that does not pay a dividend. But if the cash flows are negative or erratic over several years, the company may be in trouble.
Despite the quantitative evidence that Mirati Therapeutics is overvalued, analysts are mostly bullish on the stock. What do they know about the stock's that trumps its weak valuation and growth potential? We will look into this question in a future report focusing on qualitative factors that might be favoring MRTX.