Transurban Group (ASX: TCL) shares are 0.97% lower at $12.82 apiece in Tuesday afternoon trading.
The S&P/ASX 200 Index (ASX: XJO) is also in the red, currently down 0.64%.
As we reported last week, the Australian Competition and Consumer Commission (ACCC) has opposed the toll road operator's proposal to take a controlling stake in Horizon Roads Pty Ltd.
Horizon Roads operates Melbourne's EastLink toll road.
Transurban owns Melbourne's CityLink and is building the West Gate Tunnel.
The ACCC knocked the deal back on the grounds it would reduce competition for future toll road concessions in Victoria.
On the same day that the news broke, several Transurban directors purchased more shares.
Let's look at the possible reasons as to why.
Who's buying Transurban shares?
Three directors purchased Transurban shares for their personal portfolios on 21 September.
Transurban chair and independent non-executive director Craig Drummond purchased 10,000 shares at $12.70 per share on-market.
Independent non-executive director Marina Go snapped up 3,937 shares at $12.70 a piece as well.
New board appointee Dr Sarah Ryan made her debut investment as an independent non-executive director with the purchase of 4,000 Transurban shares bought indirectly at $12.7050 on-market.
Why are they buying?
Of course, we can only guess as to their motivations for buying.
It is perhaps just coincidence that these purchases were made on the same day the Transurban share price tanked on the ACCC news.
But typically, there are procedures that managers must go through to trade stock in their companies, and these usually take a little time.
Companies have specific rules in place that allow for certain trading windows for insiders.
ASX listing rules specifically suggest that companies might like to allow trading windows for insider buys or sales in the period immediately after major financial reports are released.
Transurban released its full-year FY23 results on 16 August.
The company revealed record proportional earnings before interest, taxes, depreciation and amortisation (EBITDA) of $2.5 billion.
Since the results were released, Transurban shares have fallen 7.8%, so perhaps these directors have also felt motivated to buy the dip.
In other news today, Transurban has announced that Henry Byrne has been appointed chief financial officer (CFO), effective 19 October.
Byrne has worked at Transurban since 2007.
He will replace Michelle Jablko, who becomes the new CEO on 19 October.