Bitcoin isn't an investment, it's a currency.
It is both, if gold was able to be used in stores (and ultra divisible) it would be a currency and still an investment. You invest in bitcoin over Fiat because it's deflatory while fiats are the other and it's rarity will go up as the amount in circulation spreads to more and more people.
Hmmmm, interesting.....so if currencies are investments then the exchange rate is dropping because
people are investing their bitcoins in dollars.
Companies, if companies held on to the Bitcoin they received (Dell,overstock,cheapair) and paid employees in it or used it for other services the price would be a LOT higher. Right now companies receive our bitcoins and instantly sell it for Fiat and raise the supply and demand can't keep up for it so that is why the exchange rate is lower.