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 Thursday, Concentrix Corp (CNXC)'s Chief Financial Officer, Andre S. Valentine, made a $69,869 buy of CNXC, purchasing 2,500 shares at a cost of $27.95 each. Valentine was up about 7.1% on the buy at the high point of today's trading session, with CNXC trading as high as $29.94 at last check today. Concentrix Corp is trading off about 1% on the day Friday.

And at Altimmune (ALT), there was insider buying on Monday, by John Gill who purchased 9,200 shares for a cost of $3.41 each, for a trade totaling $31,350. Before this latest buy, Gill made one other buy in the past year, purchasing $51,250 shares for a cost of $4.10 a piece. Altimmune is trading down about 4.2% on the day Friday.

For MarketNewsVideo.com, I'm Sayoko Murase.