Shares in iron ore producer Ferrexpo have been performing well lately but the shares are lower today.The share price of Gem Diamonds has also lost a bit of sparkle today.Engineering stocks are in demand, with Cookson Group and Atkins among the risers.FTSE 250 - RisersInterserve (IRV) 207.50p +5.60%Cookson Group (CKSN) 458.70p +5.23%Grainger (GRI) 142.30p +3.87%Enterprise Inns (ETI) 99.70p +2.78%Lamprell (LAM) 209.50p +2.65%GKN (GKN) 122.80p +2.33%Atkins (WS) (ATK) 636.50p +2.25%Meggitt (MGGT) 276.90p +1.99%BSS Group (BTSM) 263.10p +1.98%Filtrona PLC (FLTR) 175.30p +1.92%FTSE 250 - FallersNorthern Foods (NFDS) 68.60p -4.59%Ferrexpo (FXPO) 219.40p -4.19%Gem Diamonds (GEMD) 229.20p -3.62%Dairy Crest Group (DCG) 361.10p -3.45%Informa (INF) 322.40p -3.42%WH Smith (SMWH) 497.50p -3.40%Fidelity Special Values (FSV) 546.50p -3.10%Mcbride (MCB) 218.10p -3.07%Carpetright (CPR) 957.00p -2.84%PayPoint (PAY) 452.00p -2.48%