A flurry of economic data and renewed concerns about the Federal Reserve's 'exit strategy' from stimulus ensured that markets opened firmly in the red on Wednesday morning.The FTSE 100 hit intraday low of 6,507 early on before rebounding slightly within the opening hour - this was the index's lowest level since May 2nd when it closed at 6,461.Japanese markets were volatile overnight and were trading firmly lower into the close as investors were underwhelmed by Prime Minister Shinzo Abe's barrage of new plans to boost economic growth. Sentiment was also dampened by a worse-than-expected slowdown in Australian economic growth in the first quarter.Closer to home, purchasing managers' indices (PMIs) are due out in the UK and Eurozone today, as well as the all-important growth figures from the euro area. However the focus is likely to be on data from the States as markets continue to look for indications of how economic figures may influence the Federal Reserve's decision to 'taper' stimulus. All eyes will be on the ADP employment report today, which is usually seen as a rough indicator for what to expect from the official US non-farm payrolls report due out on Friday. Analysts are predicting that the economy added around 170,000 jobs in May.Concerns about the Fed scaling back stimulus prematurely had eased this week after a worse-than-expected reading of US factory activity on Monday. However, these worries were reignited yesterday after Esther George, President of the Kansas City Fed, said that the Fed should begin to scale back quantitative easing."History suggests that waiting too long to acknowledge the economy's progress and prepare markets for more-normal policy settings carries no less risk than tightening too soon," she said.FTSE 100: Tesco disappoints with first-quarter resultsSupermarket group Tesco saw shares fall this morning as like-for-like (LFL) sales across the board continued to slip in the first quarter, with its UK and international businesses suffering from the ongoing squeeze on consumer spending. Headline group sales were up 2.7% but down 2.2% on a LFL basis.AB Foods and National Grid were also in the red after going ex-dividend this morning, meaning that new investors won't be able to receive the companies' latest payouts.Plumbing and heating products group Wolseley was among the risers, rebounding after some heavy falls the day before on the back of a disappointing third-quarter update. The stock was given a lift this morning by Morgan Stanley which upped its recommendation to 'equal weight'.Chip designer ARM Holdings was also performing well after Bank of America Merrill Lynch said that it sees the recent weakness in the stock - on the back of rising competition from Intel - as a "particular buying opportunity as we believe that ARM's ecosystem is likely to prevail long term".FTSE 250: RPC gains after full-year resultsA 6.9% fall in full-year revenue at European plastic packaging group RPC wasn't enough to deter investors today with shares rising strongly from the off. The firm said it was a "robust performance in a challenging economic environment". The firm raised its total dividend per share from 14.4p to 14.9p.DS Smith, the paper and plastic packaging group, was under the weather this morning after Goldman Sachs downgraded the stock to 'neutral', saying that the share price has "limited upside" following a strong period of outperformance.Among the fallers early on were Daily Mail & General Trust, Debenhams, Grainger and Bank of Georgia after going ex-dividend.FTSE 100 - RisersWolseley (WOS) 3,180.00p +1.11%Tate & Lyle (TATE) 838.00p +0.72%Shire Plc (SHP) 2,159.00p +0.65%William Hill (WMH) 434.80p +0.65%ARM Holdings (ARM) 929.00p +0.54%Experian (EXPN) 1,218.00p +0.49%Antofagasta (ANTO) 960.00p +0.42%Eurasian Natural Resources Corp. (ENRC) 246.50p +0.41%BP (BP.) 471.35p +0.39%Randgold Resources Ltd. (RRS) 5,150.00p +0.39%FTSE 100 - FallersAberdeen Asset Management (ADN) 443.80p -4.33%National Grid (NG.) 759.50p -3.92%Tesco (TSCO) 354.30p -2.79%Marks & Spencer Group (MKS) 458.50p -1.67%WPP (WPP) 1,102.00p -1.61%Old Mutual (OML) 202.50p -1.51%Evraz (EVR) 132.00p -1.49%Schroders (SDR) 2,329.00p -1.48%InterContinental Hotels Group (IHG) 1,868.00p -1.48%Anglo American (AAL) 1,496.50p -1.45%FTSE 250 - RisersRPC Group (RPC) 423.40p +5.96%Thomas Cook Group (TCG) 128.50p +4.17%Homeserve (HSV) 271.20p +3.12%New World Resources A Shares (NWR) 104.00p +2.97%Synergy Health (SYR) 1,101.00p +2.80%NMC Health (NMC) 313.70p +2.52%PayPoint (PAY) 984.50p +1.49%3i Group (III) 348.90p +1.48%Centamin (DI) (CEY) 38.80p +1.33%Kazakhmys (KAZ) 326.90p +1.27%FTSE 250 - FallersMan Group (EMG) 106.00p -9.01%Henderson Group (HGG) 162.20p -3.22%Smith (DS) (SMDS) 234.50p -2.74%Synthomer (SYNT) 192.50p -2.53%Investec (INVP) 453.50p -2.47%Bank of Georgia Holdings (BGEO) 1,814.00p -2.42%Daejan Holdings (DJAN) 3,924.00p -2.14%International Personal Finance (IPF) 503.50p -2.04%Balfour Beatty (BBY) 223.50p -2.02%Debenhams (DEB) 92.80p -1.95%FTSE TechMARK - RisersArk Therapeutics Group (AKT) 0.43p +10.26%Oxford Biomedica (OXB) 1.65p +5.10%Skyepharma (SKP) 47.00p +4.44%Xaar (XAR) 650.00p +3.09%Innovation Group (TIG) 28.00p +0.90%Optos (OPTS) 121.00p +0.83%Sepura (SEPU) 114.25p +0.66%BATM Advanced Communications Ltd. (BVC) 20.44p +0.31%Kofax (KFX) 332.00p 0.00%Triad Group (TRD) 6.50p 0.00%FTSE TechMARK - FallersE2V Technologies (E2V) 119.00p -1.65%Wolfson Microelectronics (WLF) 209.00p -0.95%Parity Group (PTY) 31.25p -0.79%NCC Group (NCC) 112.56p -0.39%Kofax (KFX) 332.00p 0.00%Triad Group (TRD) 6.50p 0.00%Antisoma (ASM) 1.70p 0.00%Torotrak (TRK) 30.12p 0.00%Promethean World (PRW) 15.38p 0.00%Gresham Computing (GHT) 84.50p 0.00%