Chevron is writing down as much as $11 billion worth of assets, and it could cost the entire market.

Howard Silverblatt, senior index analyst at S&P Dow Jones Indices, said that depending on the final charge, it could reduce 2019's fourth-quarter overall S&P 500 earnings by $1.32 per share.

That would represent a big chunk of the fourth quarter's earnings as companies in the index are estimated to earn $40.40 a share in the current quarter, according to S&P Dow Jones. The whole S&P 500 is expected to earn $158.50 a share for the full year, according to estimates.

This is a big impact for the 24th-largest company in the index.

On Tuesday, Chevron said that the write-down of between $10 billion and $11 billion would be for the current quarter as the company revalues some of its assets, including shale gas production sites in Appalachia and deep-water projects in the Gulf of Mexico.

The nation's second-largest oil company also announced a $20 billion capital spending budget for 2020, and said it was considering offloading some of its natural gas projects as prices continue to falter.