bigdec, the question I posed was: where would MT take the value of the 50 daily SMA from? It cannot calculate it from the intraday data. It can only calculate it from the historical data for the symbol, and there is no guarantee that the historical data is there or that it is up to date. If you never opened a historical chart for the symbol, and never backfilled on the historical chart, or if you did that, but a few days ago and not since, MT would have no way to calculate the value.
What *you* could do, if you wanted to, would be to open a historical chart for the symbol, put a 50 day SMA on it, note the value, then put a horizontal line indicator on the intraday chart with that value. Yes, it is a bit of work, but you would only have to do that once per day.