Europe's main share indexes in London, Frankfurt and Paris all sank, and Wall Street futures were pointing down too after the latest batch of disappointing Chinese data had made for another twitchy Asian session.
Frankfurt's export-heavy DAX and Britain's domestic-focused FTSE 250 were both staring at their fourth consecutive month of falls.
For the DAX it is the worst run since the back end of 2008 and was made worse again as Deutsche Bank shares fell to an all-time low as police searched its headquarters for a second day in a money laundering scandal linked to the Panama Papers.
November's real humdingers though have been oil and Apple which have plunged 21 percent and 18 percent respectively, the worst month for either since the financial crisis a decade ago.
"Expectations at the start of the fourth quarter were for a melt-up in risky assets, but two of the biggest trends have been a reversal of some of the few returns we have seen this year, which have been in oil and in tech," said head of macro strategy at State Street Global Markets' Michael Metcalfe.
"Also the market seems to be going into the G20 meeting with very low expectations of a ceasefire in the trade war. That may very well be correct but politics has proved very hard to predict this year."
Anticipation ahead of that meeting ensured cautious moves in the currency and bond markets.
The dollar index was a touch firmer at 96.86 .DXY -- having slipped this back this week after Federal Reserve chief Jerome Powell left investors wondering whether the US central bank may be nearing the end of its current rate-hike cycle.
In early afternoon London trade, the euro fetched $1.1360 , down 0.25 percent as euro zone inflation data came in softer than forecast.
The dollar was flat at 113.52 yen while sterling shuffled around at just under $1.28 having been lifted slightly this month by UK Prime Minister Theresa May securing a Brexit transition deal with the EU.
"We believe that Powell has not turned dovish but is simply toning down his hawkish tilt," said Philip Wee, a currency strategist at DBS, forecasting another hike in December and as many as four next year.
US money markets though, where the real money sits, are now pricing in only one rise next year, and the yield on two-year US Treasury notes, sensitive to Fed shifts, is at 2.81 percent from almost 3 percent earlier in the month.
ARGENTINE TANGO
Markets could well be in for a volatile December if Trump and Xi fail to de-escalate their trade war at talks at this weekend's G20 meeting in Argentina.
Data on Friday added to the anticipation, showing that growth in China's vast manufacturing sector had stalled this month for the first time in more than two years.
"This is not a good year for multilateralism," a German government source told Reuters about the prospects for a G20 statement at the end of the meeting on Saturday. The negotiations are "very, very difficult."
MSCI's broadest index of Asia-Pacific shares outside Japan ended down 0.2 percent with Korean shares one of the main drivers after the country's central bank lifted its interest rates in a widely expected decision.
In Japan, the Nikkei ended 0.4 percent higher, while Chinese blue-chips, which have had a relatively steady month all considered, also advanced 1 percent.
US S&P e-mini futures ticked down 0.3 percent, pointing to a weaker Wall Street session on Friday after a mixed overnight performance.
The Dow Jones Industrial Average fell 0.11 percent, the S&P 500 lost 0.22 percent, and the Nasdaq Composite dropped 0.25 percent on Thursday.
Boeing Inc, the single largest US exporter to China, dropped 0.9 percent in premarket trading. Other trade-sensitive stocks including General Electric Co declined 2.6 percent and Caterpillar Inc 0.2 percent.
Trump himself had sent mixed signals saying: "I think we're very close to doing something with China but I don't know that I want to do it," as the money coming in from his tariffs was so lucrative.
Back in the oil markets, crude was starting to slip again having tried to steady on news that Russia is increasingly convinced it needs to reduce oil output along with the Organization of the Petroleum Exporting Countries (OPEC).
OPEC and its allies are meeting in Vienna on Dec. 6-7. Brent and US WTI crude were both down around 0.6 percent at $59.51 per barrel and $51.38 a barrel. Spot gold barely budged at $1,223 per ounce.