The Chicago Mercantile Exchange (CME) Bitcoin open interest (OI) has reached an all-time high of 172,430 BTC ($11.6 billion). In the past five trading sessions alone, the OI has increased by 25,125 BTC. This surge is comparable to that of June 2023, when an OI rise of 26,525 BTC preceded a BTC price jump from $25,000 to $30,000. Similarly, an October 2023 OI increase of 25,115 BTC heralded a BTC rally from $25,000 to $40,000. Analyst Vetle Lunde attributes the current OI increase primarily to direct investors, rather than ETFs. This suggests a bullish sentiment in the market.