The BHP Group Ltd (ASX: BHP) share price ended September with a bang, but it was mostly downhill in October.
Shares in the S&P/ASX 200 Index (ASX: XJO) mining giant closed out September trading for $45.96. When the closing bell sounded on 31 October, those same shares were changing hands for $42.64 apiece, down 7.2% over the month.
For some context, the ASX 200 declined by 1.3% in October.
Here's why the BHP share price came under heavier selling pressure.
What sent the BHP share price tumbling?
As you're likely aware, iron ore counts as BHP's top revenue earner, with copper coming in at number two.
Both industrial metals enjoyed a big lift in September and into early October on the back of several sizeable economic stimulus measures from the Chinese government. But further stimulus announcements from China fell short of market expectations.
This saw the iron ore price tumble from US$122 per tonne on 7 October to US$104 per tonne at the end of October, down 14.7%.
It was a similar story for the copper price, according to data from Bloomberg. The red metal was fetching US$10,085 per tonne on 2 October before sliding to end the month at US$9,538 per tonne, down 5.4%.
With traders downgrading their medium-term outlook for copper and iron ore prices amid lower demand expectations out of China, the BHP share price took an unavoidable hit.
What else happened with the ASX 200 mining stock?
While the BHP share price couldn't escape the pressures from slumping copper and iron ore prices, the ASX 200 miner did release a relatively strong quarterly update on 17 October.
Among the highlights, BHP produced 71.6 million tonnes of iron ore over the three months, up 3% year on year. This was driven by strong supply chain performance alongside increased capacity following its Port Debottlenecking Project (PDP1).
And copper production increased by 4% during the quarter to 476,000 tonnes, spurred by higher grade and recoveries at the company's Escondida mine.
BHP CEO Mike Henry also sounded a positive note on expectations of future stimulus measures from China.
"China has announced a series of monetary easing policies in an effort to support economic growth, and has indicated more significant fiscal stimulus is on the horizon," Henry said.
BHP share price gets a lift from Samarco settlement
Bucking the downward trend over the month, the BHP share price closed up 1.3% on 28 October. That's when the ASX 200 miner announced it had reached a R$170 billion (AU$47.9 billion) agreement to settle the Brazilian legal action over the Samarco dam failure.
The funds will support the people, communities, and environment impacted by the 2015 Samarco Fundao iron ore tailings dam collapse. Samarco, a 50/50 joint venture between BHP Brasil and Vale, owned and operated the Fundao Dam.
The accident killed 19 people and caused massive environmental damage. It also saw investors bidding down the BHP share price at the time.
