DMA is lagging indicator.For example in 10-DMA a PEAK or TROUGH is indicated
after 10 periods ,hence it is given rise to EMA. In EMA the lagging effect is MINIMIZED.DMA is popular because the construction is quite easy.
EMA-10 is often used as SIGNAL LINE since it follows the TREND on small time
frame.
What for you use EMA-499?
Well explained Columbus. Just to add 2 cents from my side
1) DMA gives equal weight to price action of all days. That means, it is just simple average of prices over the period.
2) EMA uses some kind of weights for each day (don't want to complicate this post with forumlas but one can easily find it on the net). Higher weight is given to the recent days. So that makes MA better reflection of current price action.
If you timeframe is long (say 200days) then EMA/DMA gives more or less same value.. but if timeframe is short, (say 10d) then you can see the difference. Specially when last 1 or 2 bars were long. or if there was long bar 10days back and it is just dropping off from calcuation tomorrow.
Happy Trading.