Bitcoin and companies tied to cryptocurrencies extended a nearly two-month swoon Monday, tracking with a broader market sell-off in technology companies that many see as overvalued.

Bitcoin, which soared to a record $126,210.50 on Oct. 6 according to crypto trading platform Coinbase, slid more than 7% to below $85,000. That's a decline of 33% in just eight weeks.

Stocks across the crypto industry tumbled, with Coinbase Global sinking 4% and online trading platform Robinhood Markets losing 5.2%. Bitcoin mining company Riot Platforms dropped 7%.

Strategy, the biggest of the so-called crypto treasury companies that raises money just to buy bitcoin, tumbled 8.8%. The company has reported holding 649,870 bitcoin. As of 11 a.m. ET Monday they were worth about $55 billion.

American Bitcoin, in which President Donald Trump's sons Eric Trump and Donald Trump Jr. hold a stake, fell 9.3% and is now down 43% since Sept. 30.

Analysts point to a number of factors that have led to the sell-off in bitcoin and other crypto investments, including a broad risk-off sentiment that has gripped markets this fall, sending investors toward safer havens such as bonds and gold.

Bitcoin futures are down nearly 24% in the past month. At the same time, gold futures are up almost 7%.

In a research note to clients last week, Deutsche Bank analysts also attributed the recent declines in crypto to institutional selling, other long-term holders collecting profits and a more hawkish Federal Reserve. Stalled crypto regulation has also contributed to the uncertainty, Deutsche Bank said.

"While volatility remains inherent, these conditions indicate Bitcoin's portfolio integration is being tested, and raises questions of whether this is a temporary correction or a more prolonged adjustment," the analysts wrote.