The UK equity market experienced unprecedented levels of market volatility over September, taking its lead from the US. In this environment, economic news took a back seat in determining stockmarket direction. The Hoare Govett plus AIM ex IT index fell 16.5%. UK interest rates were left on hold at 5.0% on 4 September for the fifth consecutive month.August consumer prices index (CPI) rose to the highest level in 16 years to 4.7% year-on-year, according to the Office for National Statistics, versus 4.4% yo- y in July. The CPI figure was driven higher by rising gas and electricity bills, although this was partially offset by a fall in petrol prices.Bank of England Governor Mervyn King wrote an explanatory letter to Chancellor Alistair Darling, pointing out that, while inflation is expected to peak soon near 5.0%, it was likely to remain above the target 2.0% well into 2009. Elsewhere in the economy, August unemployment rose the most in 16 years (claims for jobless benefits rose 32,500 to 904,900), data continued to point to a slowing housing market, and sterling fell against the US dollar reflecting the weak outlook for the economy.