It is usually uneventful when a single insider buys stock. However, When quite a few insiders buy shares, as it happened in Tourmaline Oil Corp.'s (TSE:TOU) case, it's fantastic news for shareholders.

While insider transactions are not the most important thing when it comes to long-term investing, we do think it is perfectly logical to keep tabs on what insiders are doing.

View our latest analysis for Tourmaline Oil

The insider, William Kirker, made the biggest insider sale in the last 12 months. That single transaction was for CA$4.4m worth of shares at a price of CA$66.37 each. So we know that an insider sold shares at around the present share price of CA$61.25. While we don't usually like to see insider selling, it's more concerning if the sales take place at a lower price. In this case, the big sale took place at around the current price, so it's not too bad (but it's still not a positive). William Kirker was the only individual insider to sell shares in the last twelve months.

Over the last year, we can see that insiders have bought 84.06k shares worth CA$5.1m. But they sold 66.00k shares for CA$4.4m. In the last twelve months there was more buying than selling by Tourmaline Oil insiders. The chart below shows insider transactions (by companies and individuals) over the last year. By clicking on the graph below, you can see the precise details of each insider transaction!

There are always plenty of stocks that insiders are buying. If investing in lesser known companies is your style, you could take a look at this free list of companies. (Hint: insiders have been buying them).

We've seen more insider selling than insider buying at Tourmaline Oil recently. In that time, insider William Kirker dumped CA$4.4m worth of shares. Meanwhile insiders bought CA$1.1m worth. Since the selling really does outweigh the buying, we'd say that these transactions may suggest that some insiders feel the shares are not cheap.

I like to look at how many shares insiders own in a company, to help inform my view of how aligned they are with insiders. I reckon it's a good sign if insiders own a significant number of shares in the company. Tourmaline Oil insiders own about CA$1.1b worth of shares (which is 5.0% of the company). Most shareholders would be happy to see this sort of insider ownership, since it suggests that management incentives are well aligned with other shareholders.