10 things you need to know before the opening bell

Here is what you need to know.

There's a hidden way for investors to score big on tax reform. Goldman Sachs says to look at downtrodden small-cap stocks for stock-picking opportunities in the aftermath of GOP tax reform.

Bitcoin flirts with $15,000. The cryptocurrency trades up 7.49% at $14,918 a coin, according to Markets Insider data. It was as low as $10,775 on Friday.

Morgan Stanley says bitcoin's true price could be zero. A note from Morgan Stanley analyst James Faucette and his team didn't give a price target for bitcoin, but said the cryptocurrency's true value could be zero because it isn't widely accepted and its acceptance is shrinking.

Israel's regulator wants to ban bitcoin-linked companies from trading on its stock exchange. "If we have a company that their main business is digital currencies we would not allow it," Shmuel Hauser, the chairman of the Israel Securities Authority (ISA), told business leaders of proposals he would introduce next week. "If already listed, its trading will be suspended."

China shuts off oil exports to North Korea. China didn't export any gasoline, jet fuel, diesel or fuel oil to North Korea during the month of November, Reuters reports, citing Chinese customs data.

Oil discoveries are at an all-time low. It is estimated that less than 7 billion barrels of oil equivalent have been discovered in 2017 through Thursday, the lowest since the 1940s, according to Rystad Energy, an oil and gas consultancy.

Consumer prices tick up in Japan. Core prices rose 0.9% versus a year ago, making for an 11th straight month of gains, Japanese government data showed.

Theranos is gearing up for a rebound. The embattled blood-testing startup has raised $100 million in secured debt funding, according to an investor letter reviewed by Business Insider.

Stock markets around the world are mostly closed. China's Shanghai Composite (-0.50%) lost ground in Asia and markets are shuttered across Europe. The S&P 500 is set to open little changed near 2,686.

US economic data flows. Case-Shiller home prices will be released at 9 a.m. ET and Dallas Fed Manufacturing crosses the wires at 10:30 a.m. ET.