Candle spikes on SPY

I've never used Metastock, but if you see a difference, it would be due to a difference in data vendors, not a policy not to show extreme prices. SC adjusts vendor data dividends, but you can also see the unadjusted data by adding a leading underscore to the symbol. In any case, I doubt data adjustment would wipe out a spike. You can see the data SC uses to create the chart under the Past Data link under every chart.