By Gertrude Chavez-Dreyfuss

NEW YORK (Reuters) - Investors in the world's largest cryptocurrency are anticipating a significant downward move after bitcoin failed to hit an all-time peak of $100,000, according to a crypto trading platform citing recent options activity.

Bitcoin ( BTC-USD ) hit a record high of $99,830 on Nov. 22, but it has since fallen more than 8% to a one-week low of 91,377.32 on Tuesday.

The best-known cryptocurrency has soared 120% so far this year and about 34% this month with the election of Donald Trump as U.S. president and a slew of pro-crypto lawmakers in Congress. Trump embraced digital assets during his campaign, promising to make the United States the "crypto capital of the planet," and accumulate a national stockpile of bitcoin.

Nick Forster, founder of onchain options decentralized protocol Derive with total trade volume of $7.1 billion, said in emailed comments on Tuesday that the so-called call-put skew index for the upcoming Dec. 27 bitcoin expiry showed a significant 30% drop in the last 24 hours, as market participants shifted toward more protective strategies.

The call-put skew, which reflects market sentiment, refers to the difference in implied volatility between calls (options to buy) and puts (options to sell). This skew still shows a preponderance of calls over puts, although it has since declined.

"It suggests traders are hedging against potential downside risks," Forster said, likely in response to BTC falling sharply. "However, pullbacks like these are not uncommon in bull markets."

Investors are looking to Dec. 27, when $11.8 billion in bitcoin options expire that could trigger major moves in either direction.

According to Foster, there is a 68% chance of bitcoin moving 16.03% lower to $81,493 or 19.9% higher to $115,579 by December 27. There is, however, a smaller probability of about 5% of bitcoin making bigger moves — a 29.49% fall to $68,429 or a 41.83% surge to $137,645 by the same date.

Derive data also showed higher odds of 45% of bitcoin hitting $100,000, from last week's 34%, with a new 4% probability of surpassing $150,000.

Forster also noted stability in bitcoin's volatility in the last seven days, with the seven-day at the money implied volatility at 63% and the 30-day level at 55%.

"This close alignment suggests the market anticipates significant movements soon."

Bitcoin has come off its high perch for now, and one of reasons cited by market participants for the decline was good old profit-taking.

Anthony Pompliano, founder and chief executive officer at Professional Capital Management, in his letter to clients on Tuesday, cited _checkonchain.com analysis, which noted that long-term holders have distributed $60 billion worth of supply in the last 30-days.