Here’s why the Rio Tinto (ASX:RIO) share price is down 20% in 3 months

It certainly hasn’t been a good three months for the Rio Tinto Limited (ASX: RIO) share price.

During this time, the mining giant’s shares have lost 20% of their value.

This means Rio Tinto’s shares have now given back all their year to date gains and some more.

Why is the Rio Tinto share price sinking?

Investors have been selling down the Rio Tinto share price over the last three months due to significant weakness in the iron ore price.

For example, last week the spot benchmark iron ore price dropped below US$100 a tonne before rebounding to close the week at US$111.33 a tonne.

This compares very unfavourably to the price the steel making ingredient was commanding in May. At that point, the spot price was up as high as US$230 a tonne.