The molecule that matters most to understanding SABIC's 2024 financial performance is not polyethylene or methanol. It is ethane. Specifically, it is the price of ethane at the point where Saudi Aramco delivers it to SABIC's crackers along the Eastern Province, because that single number, more than any product price movement or demand signal from China, determined the margin architecture for the entire Saudi chemicals sector last year.

Start with the physical reality.

Saudi Aramco raised domestic ethane feedstock prices by 43 percent, moving from $1.75 per million British thermal units to $2.50 per million British thermal units, with the change taking effect on January 1, 2024.

For a company of SABIC's scale, that is not a rounding error.

SABIC itself faced an estimated 1.0 percent increase in cost of sales, but in absolute terms the impact was the largest of any producer under analyst coverage, reaching approximately SAR 1.195 billion.