... the cheap oil coming from ISIS and Saudi Arabia
Ok, stop reading Fox news. This is nothing to do with ISIS. They aren't huge suppliers of oil.
For Americans ...
OPEC (the group of countries that produce oil) have teamed up together to smash American shale. They have lowered the price of oil to make fracking unprofitable. Once frackers go bust (due to huge investment and now continual losses) they will put the price up again. Saudi are the world's biggest supplier and refused to push the price back up.
As noted, Russia is dependant on oil and gas exports for a huge amount of its gdp. This has hurt the Rubel. Now Western media is also saying Western sanctions over the Ukraine are playing a part, but I think that's more a combination of wishful thinking and propaganda to the Western world to make out their tactics are effective. I don't think its making that much difference to be honest.
Anyway, Russia then made a huge screw up 2 days ago. First they spent $70bn to arrest the decline in their currency. They managed to halt the decline for a mere 3 hours. It was the equivalent of saying "Investors, please don't leave Russia, we'll give you $70bn to stay" and investors said "Thanks, we'll take that and we're still leaving". It was a massive fuck up and has shown the world Russia's central bank is panicking and it doesn't know what it is doing. So investors smell blood. Add to that Russia just pushed interest rates to 17%. Now that doesn't have immediate impact but it will bite them hard in the long term. No one is going to invest in property for example, especially foreigners. It was double stupidity in 2 ridiculous emergency measures that did nothing to stop their currency going from 60 rubles to the dollar to 75 Rubles in the same day!
Russia has almost half a trillion dollars of bonds in the international market. Whilst Moody's etc have not yet changed the rating, most investors now classify these as junk. No one wants anything Russian. I don't think they will do the right things to change this and I fear Russia's economy is toast.