I've seen a couple of days where the price appears to drop to zero, perhaps we should have a check and if the price looks wrong just not update it or try again lateR?
This plot is really useful, but I don't always remember what the tickers stand for? Any chance we could have the summary of the plot reflect the full company name and perhaps the DTD performance numbers?
Summary
User supplied summary for the plot
Daily price chart of the best-performing S&P 500 stock. Updated daily.