Why did the South32 share price melt more than the market today?

A man's eyes pop behind the ice cream melting in his hands, making a mess.

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The South32 Ltd (ASX: S32) share price finished in the red alongside other ASX mining shares today after the United States interest rate decision caused the broader market to panic.

The South32 share price dived 3.16% to close Thursday’s session at $3.68.

The S&P/ASX 200 Materials (ASX: XMJ) was the worst-performing sector index today, down 2.96%.

The S&P/ASX 200 Index (ASX: XJO) fell 1.84%.

Let’s look at what happened.

South32 share price feels the heat

The fourth consecutive 0.75% increase in US interest rates isn’t great news for ASX mining shares.

Nor is the Fed Chair’s comment that “incoming data since our last meeting suggest that the ultimate level of interest rates will be higher than previously expected”. Mic drop.

US rates are now at their highest level since the global financial crisis in 2008.

What the US does in its economy tends to have a major flow-on effect on the rest of the world. That includes international commodity markets, many of which trade in US dollars.

The main metals that South32 mines are aluminium, manganese, nickel, and coal.

The first three are holding up okay but the price of coal has slipped 6.6% over the past week and 9.5% over the past month, according to Trading Economics data.

That might not sound dramatic but the market has been in a lather over ASX coal shares for some time. The coal price is up almost 130% over the past year. It hit a historical peak of above US$430 per tonne in September. So, investors have been hyped.

But the coal price has since fallen. Maybe this downturn might have investors taking profits now?

We note that South32 is one of the highest-traded shares on the ASX 200 today.

South32 share price falling since May

The South32 share price is down 9.6% in the year to date.

As my Fool colleague Tristan reported this week, South32 shares are down 28% in five months.

Why did the South32 share price melt more than the market today?