The Alumina Limited (ASX: AWC) share price has plummeted over the last week despite no news having been released by the company.
Interestingly, the company had a good day on the ASX today. That's despite the Australian Government pledging to reach net-zero emissions by 2050 ahead of next week's COP26 climate summit in Glasgow.
As The Motley Fool Australia has previously reported, Alumina is one of the S&P/ASX 300 Index's (ASX: XKO) biggest carbon polluters. It also doesn't have a plan to reach net-zero carbon emissions.
As of Monday's close, the Alumina share price is $2.11, 1.44% higher than it was at the end of Friday's session. However, it's still 8.2% lower than it was this time last week.
For context, the S&P/ASX 200 Index (ASX: XJO) has gained 0.81% in that time. The All Ordinaries Index (ASX: XAO) has also gained 0.84% over the week just been.
Let's take a look at what might have weighed on the aluminium producer's share price over the past week.
What's driving the Alumina share price down?
The Alumina share price's struggles on the ASX came amid the company's stock being downgraded by a major broker.
As The Motley Fool Australia reported on Saturday, analysts at Credit Suisse downgraded the company's stock to a neutral rating and slapped its shares with a price target of $1.90.
The reason behind the broker's downgrade was its belief that aluminium prices are unsustainable and Alumina's shares too expensive.
The price of aluminium has slipped since last week. It's been trending downwards since Wednesday after spending most of October surging higher.
According to data from Business Insider, 1 tonne of aluminium is currently US$2,868.15. That represents a fall of 1.46% over the course of today.
Additionally, Alumina seems to have suffered through a sell-off last week.
Over the last 4 weeks, an average day has seen around 12.2 million Alumina shares swapping hands.
However, Thursday saw a whopping 41.7 million Alumina shares traded. Wednesday and Friday also saw above-average numbers passed from seller to buyer.
