Yahoo Finance

$3.2 trillion in bitcoin payments processed in 2018.

https://finance.yahoo.com/news/3-2-trillion-bitcoin-payments-074536897.html

Wall Street Journal

Wild west of bitcoin options.

https://www.wsj.com/articles/could-bitcoin-hit-50-000-in-wild-world-of-crypto-options-some-say-yes-11559559601

Forbes

Altcoin market rally.

https://www.forbes.com/sites/cbovaird/2019/03/06/how-litecoin-prices-practically-doubled-this-year/#776da1256ebb

International Business Times

Bitcoin in emerging markets.

https://www.ibtimes.com/lets-help-emerging-markets-show-bitcoins-value-world-2777572

ChinaZ

Bitcoin trading volume passes $2 trillion in 2018.

http://www.chinaz.com/sees/2018/1207/967563.shtml

CoinTelegraph

Bitcoin market analysis.

https://cointelegraph.com/news/bitcoin-ripple-ethereum-bitcoin-cash-stellar-eos-litecoin-cardano-monero-tron-price-analysis-dec-3

CoinDesk

Bitcoin trading volume increases 61% from 2017.

https://www.coindesk.com/down-more-than-70-in-2018-bitcoin-closes-its-worst-year-on-record

NewsBTC

BTC/USD market overview.

https://www.newsbtc.com/2018/12/04/btc-usd-price-analysis-fundamental-diverges-positive-bitcoin-bulls/

Bitcoinist

Bitcoin trading volume increased in 2018 despite bear market.

https://bitcoinist.com/bitcoin-trading-volume-2-trillion/