A broad rally for US equity markets unravelled in the final hour of trading as fresh coronavirus concerns weighed on investor sentiment - Dow inched +10.5-points or +0.04% higher, unwinding an earlier rally of as much as +564-points or +2.2%. Dow constituent Pfizer Inc (up +4.08%) and BioNTech SE (+10.55%) rallied after the pharmaceutical groups said two of their vaccine candidates to protect against the coronavirus had received Fast Track designation status from the Food and Drug Administration (FDA). Pfizer and BioNTech said they expect to start the next phase of the vaccine trial later this month with 30,000 subjects. The companies expect to have 100M doses of a vaccine by the end of 2020 and more than 1.2B doses by the end of 2021, according to a release. The broader S&P500 fell -0.94%, having been up over >1.5% earlier in the session and briefly pushing into positive territory for the year. Utilities (down -3.62%) and Information Technology (-2.12%) led eight of the eleven primary sectors lower. Financials rose +0.32% ahead of some key results in the sector tonight AEST. The NASDAQ shed -2.13%, logging its biggest intra-day reversal since 7 April. The technology-centric index had been up as much as +1.95%. The Nasdaq-100 - which comprises the 100-largest nonfinancial companies in the composite - briefly broke above 11,000 for the first time before settling -2.2% lower. The Nasdaq 100 has only seen an intra-day reversal of that magnitude twice – the last time was 7 March, 2000. Tesla Inc settled -3.1% lower after rallying as much as 16.2% earlier in the session (and taking its market capitalisation to a record above >US$330B, ranking the electric vehicle maker as the 10th largest company in the S&P500 and more than Toyota, Ford Motor, General Motors and Fiat Chrysler Automobiles combined). Tesla’s intra-day reversal was the largest swing from positive to negative since 30 June, 2010, according to Dow Jones Market Data. The 10 largest stocks in the S&P500 have an average of 1% of their float short sold – Tesla’s shoer interest is almost ten times that, according to Bespoke Investment Group. Moderna Inc jumped +14.7% after Nasdaq said it was adding the drugmaker to the Nasdaq-100 Index before the market opens on 20 July. The small capitalisation Russell 2000 index fell -1.34%.