Investors seeking long-term growth often wonder whether they should resort to any of the fundamental strategies like growth or value, or follow an approach that combines the best of both. Not to forget the fact that, a pure play value investor always misses the chance of betting on stocks that have bright long-term prospects. On the other hand, a growth investor often ends up investing in expensive stocks.

It has been observed that strategic mingling of both growth and value investing principles gives us a mixed investing strategy. Termed as GARP (growth at a reasonable price), this approach is getting popular with each passing day. What GARPers look for is whether the stocks are somewhat undervalued and have solid sustainable growth potential (Investopedia).

And here lies the importance of a not-so-popular fundamental metric, the price/earnings growth (PEG) ratio. Although it is categorized under value investing, this strategy follows the principles of both growth and value investing.

The PEG ratio is defined as: (Price/ Earnings)/Earnings Growth Rate

It relates the stocks P/E ratio with future earnings growth rate.

While P/E alone only gives the idea of stocks, which are trading at a discount, PEG while adding the GROWTH element to it, helps to find those stocks that have solid future potential.

A lower PEG ratio, preferably less than 1, is always better for GARP investors.

Say for example, if a stock’s P/E ratio is 10 and expected long-term growth rate is 15%, the company’s PEG will come down to 0.66, a ratio which indicates both undervaluation and future growth potential.

Unfortunately, this ratio is often neglected due to investors’ limitation to calculate the future earnings growth rate of a stock.

There are some drawbacks to using the PEG ratio though. It doesn’t consider the very common situation of changing growth rates such as the forecast of the first three years at very high growth rate followed by a sustainable but lower growth rate in the long term.