3i Group (III) directors and insiders have piled into the private equity giant’s shares since their 16% slump last Thursday, snapping up over £3.9m of stock in a sign of their apparent confidence.

On 13 November, the day of the half-year results that warned of slowing sales growth at Action, the discount retailer that makes up nearly three quarters of 3i’s £29bn portfolio, chief executive Simon Borrows spent over £1m on 30,000 shares.

He was accompanied by senior private equity partner Peter Wirtz who purchased 25,000 shares at £853,750.

They were followed the next day by non-executive Peter McKellar who splashed out a total of £955,260 on 29,000 shares. McKellar also chairs Partners Group Private Equity (PEY).

Also that day, chief operating officer Jasi Halai ploughed £348,657 into 10,588 shares.

On Monday, group finance director James Hatchley disclosed he had invested £509,550 in his employer.

On Tuesday Wilco Jiskoot, a person closely associated with non-exec Alexandra Schaapveld, a former investment banker at RBS and ABN Amro, showed his conviction by buying 7,800 shares for £259,350.

Despite this, 3i shares have not recovered. Having fallen from £43.02 on 10 November to £33.60 last Thursday, they have drifted lower to £33, firming 0.7% today, valuing the FTSE 100 company at £32.7bn.

The rapid decline has cut the hefty share price premium from 48% to 14%, making them a lot less expensive if Action’s slowdown is not more serious.

Over five years, 3i is the second best-performing London-listed investment company. It has delivered a 243% total return to shareholders, behind CQS Natural Resources Growth & Income (CYN) which has provided 260%, according to Winterflood data.