Daily margin yes… you want to look at day trading margin unless you plan on holding longer… Which the spreads are daily and close when SI pit closes so you probably don’t want to be holding futures that long anyway. For ratios on hedges use the scanner. Silver has the highest ratio of spreads to underlying to hedge with i persnally don’t like silver, copper, or ustech 100 spreads for that avery reason they tick to wide. Their binaries are find. and all other spreads are fine but i personally avoid spreads on those three markets.
There is a mini but it is a different size. See cmegroup.com globex, metals to learn more about the different contracts under contract specs. It is a different instrument but really it is just a smaller size otherwise there would be arbitrage. There will be a slight variation in the chart but it should not be to significant. The bid/ask spread will be lighter as the volume will be lighter.
Click on this link and then click contract specs to see what future symbol goes with what nadex contract: http://apexinvesting.net/member/core-calc “http://apexinvesting.net/member/core-calc”