The number of oil rigs operating in the U.S. was unchanged this week after declining by two in the prior week, according to oil services giant Baker Hughes.

Oil prices have risen to the highest level since the end of March, due in part because of a decline in U.S. oil inventories and an expected boost in demand for gasoline as the U.S. heads into summer.

The price of a barrel of Brent Crude rose to a high of $120.13 on Friday before retreating to $119.76. The price of a barrel of West Texas Intermediate rose to a high of $119.46 and was trading around $119.12 by midday. The average price for a gallon of gasoline hit an all-time high of $4.761 on Friday.

The OPEC+ cartel agreed on Thursday to raise its production limits faster but that appears not to have dented the confidence of traders that oil prices will continue to head higher. Analysts believe that some OPEC member nations will not be able to quickly raise production to fill the higher quotas.

U.S. oil producers are wary of expanding production for fear that regulators will adopt punitive rules aimed at combating climate change. Financing for expanded production has also become scarce as major banks have backed away from fossil fuel projects under political pressure.

Perhaps most importantly, large institutions have poured money into so-called sustainable funds that looked to environmental, social, and governance factors when making investment decisions. These funds shun fossil fuel investing. According to Deliote’s Center for Financial Services, professionally managed assets with ESG mandates swelled to $46 trillion globally in 2021, representing nearly 40 percent of all assets under management. The result of this is that it has become incredibly hard to raise funds for expanding fossil fuel production. So even oil prices above $100 a barrel are not attracting capital into the sector.

In a recent episode of Bloomberg’s Odd Lots Podcast, Goldman Sachs’ top commodities strategist describes ESG investing as “a blunt instrument that is reducing capital flows into a very critical sector.”