US equity markets extended their poor start to the fourth quarter amid mounting concerns around economic growth - Dow tumbled -494-points or -1.85%, breaking below its 50-day and 100-day moving averages. The slide of -3.14% over the past two sessions represents the worst start to a quarter since the last three months of 2008, when the Dow slumped 19.4% in the fourth quarter. The broader S&P500 -1.79%, with the Energy sector (down -2.61%) leading the index below is 100-day moving average. All eleven primary sectors closed in the red for a second consecutive session (the first time that has happened since late December 2018), with ten of them logging falls of at least 1.2%. Both Ford Motor Co (down -3.26%) and General Motors Co (-3.96%) fell after reporting disappointing quarterly sales. The -3.02% drop over the past two sessions marks the S&P500's worst start to a quarter since the indice's -5.49% slide to start the fourth quarter of 2009. The NASDAQ -1.51%., with Amazon.com Inc, Apple Inc and Google parent Alphabet Inc all dropping at least 1.3%. Tesla Inc fell a further ~3.6% in after-hours trading (after falling -2% in the regular session) after the electric-car maker reported disappointing third-quarter deliveries of ~97K vehicles versus analysts' forecasts for ~99K. All three benchmark indices posted their steepest single day slide since 23 August. The Nasdaq (down 2.7% so far in October) and the small capitalisation Russell 2000 index (falling -1.9% overnight and down -3.1% over the past two sessions) also marked their worst starts to the quarter since 2009.