Ryanair boss Michael O’Leary has pocketed more than £16m from the sale of a stake in the low-cost airline. He sold 5m shares, at €3.75 each, for €18.75m (£16.29m) and still owns 60m shares, or 4% of the business. Their value has risen from €2.80 in March and €2 last October.

More than 5m passengers flew Ryanair last month, up 9% on May a year ago. At last week’s full-year results, O’Leary said he expects traffic to rise by 15% this financial year to 67m and after-tax profits of €200m or €300m.

Ryanair posted a loss of €180m after taking a €222m hit on its stake in Aer Lingus. Underlying profit came in at €105m in the year to March, down 78%. Revenues rose by 8% as air fares fell 8%, while traffic grew 15% to 58.5m.

Scottish dairy group Robert Wiseman saw its finance director, William Keane, halve his stake last week. He sold 20,000 shares at 380p each to raise £76,000, reducing his holding to 21,100 shares. It reported an 8.6% drop in profit to £35.1m.

Directors have in-depth knowledge of their businesses so it can pay to track their moves. Every week Digitallook.com reveals those bosses who have bought or sold big stakes.