By mining for Bitcoins, as long as the markets remain active you can basically make money for nothing. But the problem is, mining is such a tough gig now that it is hardly worth it. Turning your computer into a miner will likely make it noisy and heat up. It would likely take you a long time to even mine a single Bitcoin, by which time you probably would have spent more on electricity. However, if you have access to some serious computing power and you don't have to pay the bills, you could make some easy money here.
The more realistic way of making a million with Bitcoins is going to be trading them through the most prominent exchanges, such as Coinbase. Back in 2011, you could have bought Bitcoins for $10. Selling them at $1,000 today would have delivered a profit of $990 per Bitcoin. Basically you should have bought about 1,000 Bitcoins back when they were cheap. This would have cost you around $10,000 in 2011, making you a millionaire today.
Making a million with Bitcoins today is probably still possible, but you will need some capital. Bitcoins can fluctuate many percentage points every day (on May 22, 2017 the price jumped up 10%). Day trading Bitcoins is going to be risky, but where is there is volatility there is opportunity. Otherwise, you need to take a longer-term approach and conclude whether or not you think Bitcoin will be successful. If you think Bitcoin is going to be traded by foreign exchange dealers, market makers and institutions one day, you might want to go long. Buying right now would be incredibly risky; the price chart is screaming “bubble”, but your point of entry is up to you. Don't expect to see more of the same fast growth now though.
On the other hand, if you have a strong conviction in the downfall of the Bitcoin, you need to short the cryptocurrency in any way you can. This would be an extremely risky endeavor still, but if the Bitcoin market is truly destined for failure, why not get rich when the bubble pops? To short Bitcoin, you will either need to get creative or join an exchange which allows you to do so.
It's important to remember that Bitcoin is a currency – not a stock or bond. This means that “investing” in it is like investing in a currency. You're essentially hoping the value of Bitcoin relative to your native currency goes up.
The easiest way to invest in Bitcoin is to simply get a Bitcoin wallet and buy Bitcoins. We recommend Coinbase for U.S. investors – it's the easiest, links to your bank account, and allows you to buy and sell Bitcoins. Plus, if you buy $100 USD in Bitcoins, Coinbase will give you a $10 bonus! That's awesome.
If you want to invest in an ETF through your broker, check out the GBTC at Stockpile. This ETF tracks Bitcoin, and you can invest in fractional shares. Get started at Stockpile and get $5 for free. Start here.
Remember, you could also invest in Litecoin or invest in Ethereum as well.
If you are a sane individual, Bitcoins probably don't excite you too much. The risk/reward profile of the Bitcoin market is not going to be very appealing to the savvy investor. This is just a chance to either make a quick buck, or lose everything. Bitcoins may well take off in the real-world in the future, but then again what would stop another cryptocurrency from emerging and defeating the Bitcoin, especially if it was indeed better?
So in conclusion, if you want to be a Bitcoin millionaire, you need to hijack someone else's hardware and get mining for an extended period of time (and cash out before you get penalized or arrested). Failing that, you need to either day trade Bitcoins and take advantage of the short-term price volatility, or make an extremely risky long or short bet on the long-term success or demise of the Bitcoin.
And most importantly, you need to entrust operations with bitcoin to professionals. They will correctly invest in the mining of crypto-currency and in crypto-currencies for you.