(ShareCast News) - With the share price of SIG plummeting since its third quarter trading update last week, two directors are doing their bit to show they have confidence in the company.The FTSE 250-listed building products company said on Thursday that it expects to report a fall in underlying pre-tax profit for the year as a result of challenging market conditions in mainland Europe.It now expects full-year underlying pre-tax profit to be within the range of £85m to £90m, lower than the £98.1m reported in 2014.Chief executive Stuart Mitchell and finance director Douglas Robertson both threw in over £13,500 each to back the company.It hasn't done much to give the market confidence, with shares down 1.5p (1.09%) mid-afternoon Monday to 136.1p per share.Meanwhile two of Frontier Developments' management have exercised a number of their options in the AIM-listed company.Chief creative officer Jonathan Watts and chief financial officer Neil Armstrong took a giant leap and exercised 30,000 and 12,500 share options respectively.Each sold about a third of their new shares to meet the exercise price and any associated tax liabilities.Top Director BuysPorta Communications (PTCM) Director name: Mr Raymond McKeeve Amount purchased: 304,272 @ 9.50p Value: £28,906SIG (SHI) Director name: Mr Stuart MitchellAmount purchased: 10,000 @ 135.28p Value: £13,528SIG (SHI) Director name: Mr Douglas RobertsonAmount purchased: 10,000 @ 135.28p Value: £13,528Top Director SellsFrontier Developments (FDEV) Director name: Mr Jonathan (Jonny) Francis Watts Amount sold: 19,370 @ 230.00p Value: £44,551Frontier Developments (FDEV) Director name: Mr Neil ArmstrongAmount sold: 7,474 @ 230.00p Value: £17,190