The symbolic price threshold was reached late Monday.
The world's most popular coin was more than 12% lower on the day, and more than 50% off its all-time high.
The last time the digital asset traded under $30,000 was in July of 2021.
A multi-day sell-off has caused much of the market to fall.
The last 24 hours has seen a 10% decline in the market. The S&P 500 fell to its lowest level in more than a year, as all three major stock indexes closed lower.
The stock market has been on a steady decline since Thursday, when the index posted its worst single-day drop since 2020.
Some analysts say that the correlation between the movement of tech stocks and the movement of major cryptocurrencies is a challenge to the argument that the currency is an inflation hedge.