The breathtaking fall in the oil price shows no sign of slowing. After climbing to $86 a barrel in early October, the slump in the price of Brent crude since has been dramatic.
In little over a month, Brent crude entered a bear market, down more than 20% from that high. Now losses from that peak are approaching 30%, as crude trades at $61 a barrel, down 2.6% today, marking a one-year low. Our exclusive Accumulator data table captures some of this fall, with oil having lost a quarter of its value in pound terms over the last month.
As UBS analyst Jon Rigby has pointed out, oil has been falling at roughly the same pace as its late 2014 slump when, in the face of tumbling prices, the Opec cartel of oil producing nations decided not to cut output. And that was just a staging post in its crash from $115 to $27 in the space of 18 months.
One of the catalysts for the fall has been the impact of US sanctions against Iran. Before their introduction, they drove the oil price higher on the basis they would curtail supply.
But a steady increase in output from other producers, coupled with the US decision to grant exemptions for a number of Iran's biggest oil customers, has produced the opposite effect.
Now, the slump in the oil price and the fall in US stock markets appear to be feeding off each other.
Tuesday's heavy 6% fall in the oil price was attributed to fears over global growth, amplified by stock market falls. And stock market falls have been blamed, in part, on the fall in the oil price sparking investor nerves.
The S&P 500's 3.6% loss over the week to yesterday stands out in our Accumulator table. That loss is softened by the pound's rise against the dollar over those five days: for US investors it was more painful. All the gains made in the recovery from Red October's losses have now been wiped out.
Laura Frost, fixed income investment director at M&G, said bearish investors were now driving the US stock market.
'After more than two years of US equities trading above their 200-day average, in which bullish-investors were in control, the sell-off... has reversed the situation.
'The S&P 500 index now trades below its 200-day average, which puts the more pessimistic bears in control.'
You can access The Accumulator here.