UK stocks opened slightly lower on Tuesday morning after the Bank of Japan's (BoJ) policy announcement overnight failed to live up to expectations.After a two-day meeting, the BoJ set a 2.0% inflation target and pledged to embark on a Fed-style unlimited asset purchase programme. Meanwhile, the central bank left its benchmark rate unchanged at the prior range of zero to 0.1%. However, the promised increase in asset repurchases will not come until January 2014, later than at least some had hoped. Somewhat ironically, strategists at Credit Suisse this morning announced their decision to trim their overweight position in UK equities to pay for their recent upgrade to Japan. They said: "The FTSE 100 is a defensive market (by sector composition) and thus tends to underperform when economic lead indicators and global equity markets rise (we remain positive on equities and the global economy on a three- to six-month view)." Nevertheless, they continue to overweight the UK. Volumes to pick up; markets await German ZEWAccording to market analyst Craig Erlam from Alpari, trading volumes are expected to pick up today "as traders return to their desks in the US following Martin Luther King Day".He noted that corporate earnings season will resume on Wall Street with heavyweight groups Verizon Communcations and Johnson & Johnson reporting before the opening bell. "Both companies tend to report better-than-expected earnings about half the time, so a higher figure today should see a positive reaction in the stocks shortly after the open in the US," Erlam said.On this side of the Pond, markets will be keeping a close eye on the German ZEW economic sentiment survey this morning, which is expectated to improve from 6.9 to 12.0 in January."After a subdued European session yesterday saw modest gains investors will be turning their attention back to the state of the German economy, after last week's disappointing annualised gross domestic product numbers," said Michael Hewson, the senior market analyst at CMC Markets."Today's January German ZEW survey is likely to give clues as to investor sentiment, however it would be a mistake to place too much stock in it given it is largely a reflection of market trading conditions which have been relatively benign of late."FTSE 100: SABMiller impresses with Q3 resultsBeverages giant SABMiller, the company famous for Miller Lite and Foster's brands, said that trading in the third quarter was in line with expectations with revenue growth accelerating from the first six months of the year, causing shares to edge higher.Fresnillo was in the red despite exceeding production forecasts in 2012: gold output totalled 473,034 ounces, up 5.4% year on year, was above the 460,000-ounce target.InterContinental Hotels gained after saying that it is to receive $31m in damages from FelCor Lodging Trust, which is removing eight of its hotels from the chain's control.Oil titan Tullow was in demand after completing the purchase of Spring Energy Norway AS. The company announced that the acquisition had already brought success for Tullow: last week, the company was awarded 13 licenses, of which four were operated in Norway's 2012 Awards in Predefined Areas licensing round. FTSE 250: Ocado gains with management changeOnline food company Ocado was a high riser after unveiling Sir Stuart Rose, who was formerly the Executive Chairman of the British retailer Marks & Spencer, as its new independent Non-Executive Director and Chairman Designate, effective from March 11th. Two months later the City grandee will become Chairman, following the group's annual general meeting on May 10th.Residential landlord Grainger rose after creating the GRIP unit trust with APG Strategic Real Estate Pool to acquire a residential property portfolio worth £349.4m.Gold miner African Barrick Gold rose after completing the financing for the expansion of its Bulyanhulu process plant in Tanzania.FTSE 100 - RisersSchroders (SDR) 1,925.00p +1.69%Tate & Lyle (TATE) 811.50p +1.44%Associated British Foods (ABF) 1,649.00p +1.23%Next (NXT) 4,013.00p +1.08%Kingfisher (KGF) 271.60p +1.00%Weir Group (WEIR) 1,968.00p +0.92%SABMiller (SAB) 2,982.50p +0.74%Wood Group (John) (WG.) 826.50p +0.73%Whitbread (WTB) 2,510.00p +0.68%National Grid (NG.) 699.50p +0.65%FTSE 100 - FallersFresnillo (FRES) 1,738.00p -2.08%Pearson (PSON) 1,180.00p -1.83%Royal Bank of Scotland Group (RBS) 363.10p -1.04%Vedanta Resources (VED) 1,161.00p -1.02%Standard Life (SL.) 342.30p -1.01%Vodafone Group (VOD) 160.90p -0.83%Anglo American (AAL) 1,884.50p -0.79%Aviva (AV.) 372.10p -0.75%Antofagasta (ANTO) 1,255.00p -0.71%Kazakhmys (KAZ) 775.00p -0.64%FTSE 250 - RisersOcado Group (OCDO) 102.00p +7.31%Rightmove (RMV) 1,607.00p +3.34%Grainger (GRI) 129.26p +2.34%St James's Place (STJ) 459.20p +1.75%Dechra Pharmaceuticals (DPH) 635.00p +1.52%Betfair Group (BET) 690.00p +1.40%Spectris (SXS) 2,195.00p +1.15%CSR (CSR) 367.50p +1.10%Anite (AIE) 140.00p +1.08%Ted Baker (TED) 1,166.08p +0.96%FTSE 250 - FallersDomino Printing Sciences (DNO) 633.50p -2.39%Henderson Group (HGG) 155.50p -2.02%Barr (A.G.) (BAG) 512.00p -1.92%Lonmin (LMI) 336.50p -1.87%Fidessa Group (FDSA) 1,581.00p -1.86%Heritage Oil (HOIL) 193.70p -1.68%Brewin Dolphin Holdings (BRW) 218.50p -1.58%Marston's (MARS) 132.10p -1.56%Petropavlovsk (POG) 395.80p -1.47%Bumi (BUMI) 326.80p -1.39%BC