Signet Jewelers, the largest speciality retail jewellery in the US and UK, saw its Chief Financial Officer (CFO) offload part of his stake this week following an impressive share-price rise so far this yar.Ronald Ristau, who became CFO of the dual-listed company in June 2010, sold 6,135 shares at a price of $68.37 each for a total of $419,450 (around £270,000).He was left with 37,613 shares in the firm after the transaction on June 17th.The year-to-date rise of the London-listed shares was 32% a day before the sale was made, with the stock up 54% over the last 12 months. The stock reached an all-time high of 4,787p in May after it revealed that same-store sales had risen by 6.4% in its first quarter (ended May 4th), with operating income up 10.4%.Meanwhile, on June 18th, Signet revealed a $350m share repurchase programme which "reflects our ongoing commitment to build long-term value for our shareholders, the continued confidence we have in the strength of our business, and our ability to generate free cash flow after investment in our growth initiatives".Top Director BuysKerry Group 'A' Shares (KYGA) Director name: Mr Gerard O'HanlonAmount purchased: 2,952 @ € 48.91 Value: € 144,394Terra Capital (TCA) Director name: Mr Filip Montfort Amount purchased: 100,000 @ $0.71 Value: $71,000LondonMetric Property (LMP) Director name: Mr Andrew JonesAmount purchased: 64,500 @ 109.60p Value: £70,692F&C Asset Management (FCAM) Director name: Mr Edward BramsonAmount purchased: 40,000 @ 96.13p Value: £38,452Oxford Biomedica (OXB) Director name: Mr Martin Diggle Amount purchased: 1,507,761 @ 1.70p Value: £25,632RSA Insurance Group (RSA) Director name: Mr Edward LeaAmount purchased: 13,000 @ 119.80p Value: £15,574Publishing Technology (PTO) Director name: Mr Alan MougAmount purchased: 5,000 @ 240.00p Value: £12,000Top Director SellsSignet Jewelers Ltd. (SIG) Director name: Mr Ronald ("Ron") RistauAmount sold: 6,135 @ 4,348.26p Value: £266,766TMT Investments (TMT) Director name: Mr Alexander SelegenevAmount sold: 13,333 @ $1.68 Value: $22,399