As the saying goes, there are many possible reasons for an insider to sell a stock, but only one reason to buy -- they expect to make money.

So let's look at two noteworthy recent insider buys.

On Tuesday, Magnolia Oil & Gas's CEO, Stephen I.

Chazen, made a $295,900 purchase of MGY, buying 50,000 shares at a cost of $5.92 each.

Magnolia Oil & Gas is trading off about 1.5% on the day Wednesday.

Before this latest buy, Chazen purchased MGY at 2 other times during the past year, for a total investment of $1.82M at an average of $8.06 per share.

And on Friday, CFO & Exec.

VP - Bus Dev Hof Matthew Kaes Van't purchased $84,456 worth of Diamondback Energy, purchasing 1,800 shares at a cost of $46.92 a piece.

Before this latest buy, Van't made one other purchase in the past twelve months, buying $81,839 shares for a cost of $17.23 a piece.

Diamondback Energy is trading down about 2.6% on the day Wednesday.

Investors have the opportunity to grab FANG at a price even lower than Van't did, with the stock trading as low as $44.56 at last check today which is 5.0% under Van't's purchase price.