The Chairman of South America-focused oil and gas group President Petroleum has added to his already sizeable stake in the company with the stock trading at the year's lowest level.On Thursday, the same day the stock closed at a 52-week low of 15.38p, Peter Levine spent £527,000 buying 3.4m shares at 15.5p each.The purchase, made through Levine Capital Management, raised the Chairman's interest in the company to nearly 72m shares, equal to 26.79%. He is the sole beneficial owner of the family investment fund.The day before, Levine said in a statement that operations across President's portfolio were progressing ahead of schedule and showing positive results.Yet the stock has still fallen by over a third since the start of 2013."Whilst it is impossible to ignore the share price, this is not reflective of operational matters and is diametrically opposed to the company's progress and prospects," Levine said.Top Director BuysPresident Energy (PPC) Director name: Mr Peter M LevineAmount purchased: 3,400,000 @ 15.50p Value: £527,000Mission Marketing Group (TMMG) Director name: Mr David William MorganAmount purchased: 120,000 @ 24.00p Value: £28,800KEFI Minerals (KEFI) Director name: Mr Jeffrey Guy RaynerAmount purchased: 1,000,000 @ 2.10p Value: £21,000Top Director SellsGooch & Housego (GHH) Director name: Mr Gareth JonesAmount sold: 262,645 @ 450.00p Value: £1,181,902Investec (INVP) Director name: Mr Hendrik du ToitAmount sold: 100,000 @ 431.00p Value: £431,000BC