Leading cryptocurrencies simmered down Monday after a smashing rally even as speculations around a U.S. strategic Bitcoin reserve gathered steam.

What Happened: The world's largest cryptocurrency broke beyond $107,000 for the first time this afternoon before profit-taking brought it back to $105,000, with a modest increase to $106,000 by evening.

The sentiment was upbeat following reports that President-elect Donald Trump might pass an executive order to create a national Bitcoin stockpile.

Bitcoin was already up 9.11% in December, higher than the historical average of 5.75%, per Coinglass data.

A similar pattern followed for Ethereum, which failed to decisively break over $4,000 and...