Why does the value of the SMA and EMA for the current time appear to change when I change my timescale. I'm using ActiveTrader by Fidelity, but I'm hoping there's an general phenomenon so that someone here will know what's going on.
The moving average in your platform is most likely based on closing prices of whatever time frame you're visualizing. Daily data would using daily closing prices; weekly data would use weekly closing prices; 5 minute data would use 5 minute closing prices, etc. Therefore, as you change time frame the data used to calculate the moving average changes.
Your platform may allow you to parameterize the moving average allowing you to tell it which time frame to base the calculation on. This way, when you're looking at a 5 minute chart you can still see the 50 day moving average, etc.