Received bitcoin for free in 2014 and I sold it mid-December 2017--what am I supposed to do for taxes?

[rnn47]

Long story short, in 2014 Coinbase had a sign up promotion where they gave students $10 worth of Bitcoin if they signed up with their .edu address. I took advantage of that, and sold when it hit $460 in mid-December. Now, what am I supposed to do regarding taxes? Technically, I never bought anything, so is this even considered speculation? 

[fanfare]

all investing is speculation, when you get down to it, for no one knows what the future will bring.

[maglib]

The IRS considers bitcoin property and therefore every move is considered a taxable transaction.  Gains are reportable.  you can not take net losses on personal property but only investment property.

For this, go to "Personal", "Investment Income",  "Stocks, Mutual Funds, Bonds, Other", and record each transaction with the date you sold the coins, for how much, when you acquired them, and for what.  use the section Other as your choice since you did no active moves.

You can choose to summarize reporting.  The rules to follow are provided in 8949 for property by the IRS https://www.irs.gov/pub/irs-pdf/i8949.pdf