It is really difficult for outsider to tell how long before the big bang. CB can buy each other's debt to inject liquidity or use proxy to buy up assets quietly to hold up the markets without getting noticed.
As far as I can tell a stealth stagflation has been happening for the last few years with price inflation is robbing everyone of purchasing power while income growth is flat. The reports of circular (credit card) debt at new peak confirms this.
I think when mortgagee / debtors can't afford to service their debt payment will be the turning point. The bankruptcy number does not seem to confirm that yet. However with all the bad new and job loss it has to be close.
Would next step be biggov doing tax refund /tax cut / person grant to keep the debt monster alive longer?