Bitcoin had another wild week.

With the first of two planned futures markets now open for business, bitcoin prices stacked up a fresh pile of new highs in the week ended Friday, Dec. 15. Plus, there could be new cryptos in town that steal bitcoin's thunder.

Here are the top three most important things you need to know about bitcoin from the past week.

Futures Are Live!

Cboe Global Markets Inc. (CBOE) - Get Cboe Global Markets Inc Report opened bitcoin futures Sunday night, Dec. 10, ushering in a fresh price rally that would last throughout much of the week. Just after contracts became available, both the Cboe website and cryptocurrency exchange website Coinbase were briefly shuttered.

The coin broke through $17,000 on Monday, Dec. 11, according to CoinMarketCap. Bitcoin reached a new record above $17,830 by Friday, Dec. 15.

Competition?

It's hard to think there's really anything that could hold a candle to bitcoin, but a handful of other digital currencies are trying.

Litecoin rallied so hard, Coinbase was disabled another time. By Tuesday, Dec. 12, litecoin had increased 120% since bitcoin futures opened. On Friday, Dec. 8, litecoin trading volume surpassed the billion benchmark for the first time since September to tally $1.5 billion in transactions in a day. By Tuesday, trading volume surged to $7.7 billion. By Friday afternoon, volume settled some to trade around $2.8 billion.

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Ripple also rocketed higher on bitcoin's coattails. The cryptocurrency surpassed bitcoin cash, an offshoot of bitcoin, to become the third-largest digital currency by market cap on Friday, Dec. 15. Ripple now boasts a $30.2 billion total value, about $1 billion more than bitcoin cash. Bitcoin still leads the market with a $298.5 billion market cap. That's bigger General Electric (GE) - Get General Electric Company (GE) Report , baby ($155 billion market cap)!

Ripple reached a record high of 90 cents per coin, up almost 300% in three days. The rally in ripple intensified when on Friday, Bloomberg added ripple, ethereum and litecoin pricing to its terminal. As its price and moves become more widely disseminated, ripple will likely gain further public recognition.

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Yellen the Hater

Not everyone was a fan of bitcoin this week. Most notable? Outgoing Federal Reserve Chair Janet Yellen.

In comments following the Fed's meeting that ended Wednesday, Dec. 13, Yellen said the cryptocurrency is not only speculative, but also is not a stable store of value and not a legal tender.

"Bitcoin at this time plays a very small role in the payment system," Yellen said. "It is not a stable source of value and it does not constitute legal tender. It is a highly speculative asset."

Yellen has commented very little on bitcoin during her tenure, last offering her stance on the asset in 2014. At that time, she said the Fed wasn't in an authoritative position to regulate bitcoin.

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