Concerns about the future of US stimulus continued to weigh on stocks on Monday with London's mining sector bearing the brunt of a reduction in risk appetite amongst investors.Market sentiment has been fragile in recent weeks due to heightened speculation that the Federal Reserve will taper its quantitative easing programme at its next policy meeting in September given the recent improvement in economic data as well as comments from a number of policymakers. Rising government bond yields were worrying traders today with the yield on a US 10-year Treasury note up three basis points (bp) at a fresh two-year high of 2.86%, as eyes begin to turn towards the minutes of the Federal Open Market Committee (FOMC) meeting due for release on Wednesday. Spikes in bond yields "are widely seen as unwelcomed due to the negative impact on growth at a time when economies are just starting to show tangible signs of recovery," said Market Strategist Ishaq Siddiqi from ETX Capital. Benchmark bond yields in the UK and Germany were also higher today.The FTSE 100 finished 34.26 points lower at 6,465.73.Ankit Kapur, Sales Trader at CMC Markets, said this afternoon that markets were lacking continuity as the City remains in a "holiday slumber".He said: "It appears that everyone in the City is still either asleep or on holiday with low trading volumes and a blank macro calendar unlikely to stir anyone into action in the short term as we all wait for Wednesday's Fed minutes and any clues on the potential scale of the tapering plan."FTSE 100: Miners provide a dragMining stocks were in the red on Monday as metals prices declined. Glencore Xstrata and BHP Billiton were both lower ahead of their first-half and full-year results tomorrow, respectively. Market chatter has suggested that Glencore Xstrata could write down the value of its assets inherited from Xstrata during the merger by as much as $7.0bn.Anglo American, Fresnillo, Rio Tinto and Vedanta were also registering losses with the latter down despite announcing over the weekend that it has completed the merger of two of its subsidiaries, Sesa Goa and Sterlite Industries.Pharmaceuticals group Shire edged higher after The Sunday Times said that it had hired advisory firm Lazard Ltd to help defend it against a takeover bid.Marks & Spencer was in demand as retailer launched its Britain's Leading Ladies campaign to promote its new autumn/winter fashion collection. The advertisement features stars including Helen Mirren, Tracey Emin and Ellie Goulding.Supermarket giant Tesco fell after being fined £300,000 for misleading customers over a promotion on a 400g punnet of strawberries.FTSE 250: Kentz soars on bidding war hopesOil engineering firm Kentz rocketed today after rejected two takeover proposals (one from AMEC and another from Germany's M&W Group), saying they undervalue the company. AMEC's approach valued the firm at around £680m, though City sources told the London Evening Standard that Kentz could fetch up to around £820m.Property website Rightmove and online price comparison group Moneysupermarket.com were making gains this afternoon after Westhouse Securities upgraded its ratings on the stocks to 'add' and 'buy', respectively.FTSE 100 - RisersWood Group (John) (WG.) 903.00p +2.27%ARM Holdings (ARM) 889.00p +2.18%William Hill (WMH) 428.10p +1.45%Serco Group (SRP) 615.50p +1.40%Marks & Spencer Group (MKS) 459.50p +1.37%Petrofac Ltd. (PFC) 1,262.00p +1.37%Aberdeen Asset Management (ADN) 385.50p +1.29%Diageo (DGE) 2,037.00p +1.29%Sainsbury (J) (SBRY) 388.40p +1.25%Bunzl (BNZL) 1,349.00p +1.20%FTSE 100 - FallersAnglo American (AAL) 1,492.50p -3.55%Vedanta Resources (VED) 1,200.00p -2.83%Tullow Oil (TLW) 1,034.00p -2.18%Glencore Xstrata (GLEN) 301.95p -2.08%Randgold Resources Ltd. (RRS) 5,045.00p -2.04%Standard Chartered (STAN) 1,521.00p -2.00%Lloyds Banking Group (LLOY) 75.00p -1.83%Old Mutual (OML) 194.00p -1.77%Persimmon (PSN) 1,167.00p -1.77%Rio Tinto (RIO) 3,055.00p -1.59%FTSE 250 - RisersKentz Corporation Ltd. (KENZ) 591.00p +24.19%Brewin Dolphin Holdings (BRW) 275.50p +5.56%Rightmove (RMV) 2,364.00p +4.42%Debenhams (DEB) 109.40p +3.89%Bwin.party Digital Entertainment (BPTY) 134.10p +3.87%Perform Group (PER) 549.50p +3.58%Keller Group (KLR) 1,043.00p +3.58%Halfords Group (HFD) 369.60p +3.53%Moneysupermarket.com Group (MONY) 166.00p +3.43%KCOM Group (KCOM) 85.55p +3.38%FTSE 250 - FallersOphir Energy (OPHR) 305.00p -7.58%Hochschild Mining (HOC) 232.90p -4.55%Ferrexpo (FXPO) 181.10p -3.98%Taylor Wimpey (TW.) 104.60p -3.42%Xaar (XAR) 821.00p -3.41%888 Holdings (888) 152.10p -3.31%JPMorgan Indian Inv Trust (JII) 302.00p -3.21%Kazakhmys (KAZ) 306.60p -3.13%Big Yellow Group (BYG) 422.90p -2.83%Bumi (BUMI) 214.00p -2.73%BC