(ShareCast News) - The FTSE 250 was left sitting in a puddle by mid-afternoon Wednesday, down 184.25 points (1.07%) at 17,020.78.Low oil prices were to blame for the second tier market's biggest faller Tullow Oil as well as Cairn Energy. Both Brent Crude and West Texas Intermediate sank below $35 a barrel, with Brent down 4.17% to $34.90 and WTI down 3.09% to $34.86. That was driven by tensions between Saudi Arabia and Iran, as well as data out this afternoon about US oil stockpiles."[It comes from] the realisation that Iran will do whatever it wants in terms of returning to oil-supply market, likely against Saudi wishes, the dollar rises and the prospect of higher US stocks data on account of mild weather adds to global supply glut worries," said Accendo Markets' Michael van Dulken.International events also hit miner Evraz, driven down by fears about the volatility in China. The eastern powerhouse staged an about-face from its dire start to the week, with the Shanghai Composite index gaining 2.25%.It had lost around 7% since the open on Monday, due to concerns about a slowdown in the Chinese economy, a weaker yuan and the impending lift of a no-sell order placed on major shareholders during the summer crash. Both analysts and traders in the region pointed the finger at China's crack "National Team" for the Wednesday gains. On top of that, there was particularly strong performance in the Chinese resources sector, after Premier Li Keqiang announced the country's leadership was looking at measures to reduce the coal glut.And while it was good news for Karen Hubbard, investors of B&M European Value Retail weren't too happy that the Australian was leaving her role as chief operating officer to take up the reins of Card Factory later in the year. Hubbard, who has been with the company since 2014, will join the board as CEO designate in February and take over from Richard Hayes in mid-April.Hubbard said it was "too good an opportunity to ignore". "This is a wonderful chance to lead a very successful and fast-growing value retailer with a clear leadership position in its market. The appointment followed Hayes' indication to the board of his desire to step down once a suitable successor had been found.Bwin.party featured in the risers after its latest trading update yesterday which said its fourth quarter net revenue was up 5% on the previous year, driven primarily by sports betting and casino games through mobile channels.Bwin.party said EU VAT, introduced in some of its main markets in a year ago, did have an impact on the company, and without it the growth in net revenue would have been 8%. The firm was also looking forward to a payment of approximately €10m through the sale of Visa Europe to Visa International, as Bwin.party's subsidiary Kalixa Payments is a principal member of Visa Europe. It also comes ahead of the scheduled acquisition by AIM-listed GVC Holdings on 1 February.FTSE 250 - RisersBrewin Dolphin Holdings (BRW) 313.40p 3.23%Marshalls (MSLH) 329.80p 2.81%AO World (AO.) 151.40p 2.71%Bodycote (BOY) 575.00p 2.59%JD Sports Fashion (JD.) 1,028.00p 1.28%IG Group Holdings (IGG) 793.00p 1.15%Ladbrokes (LAD) 121.50p 1.08%Bwin.party Digital Entertainment (BPTY) 131.90p 1.00%Balfour Beatty (BBY) 266.70p 0.91%Domino's Pizza Group (DOM) 1,036.00p 0.88%FTSE 250 - FallersTullow Oil (TLW) 153.40p -6.69%Amec Foster Wheeler (AMFW) 409.40p -5.65%B&M European Value Retail S.A. (DI) (BME) 267.30p -4.88%Telecom Plus (TEP) 969.50p -4.86%Evraz (EVR) 69.40p -4.54%OneSavings Bank (OSB) 312.90p -4.49%Home Retail Group (HOME) 133.10p -4.45%Aveva Group (AVV) 1,510.00p -4.43%Cairn Energy (CNE) 147.90p -4.40%Fidessa Group (FDSA) 1,903.00p -4.32%