The publisher has seen over £100m wiped off its market capitalisation this week, valuing it at little more than £250m, compared with £1.3bn a year ago.
Its shares closed last night at 92.5p and fell this morning to as low as 88.75p, less than half their value last week, before recovering slightly to 90.5p.
On Monday, Trinity Mirror warned that profits are expected to be down by 10% on the back of a weakening advertising market.
Last week prior to Trinity Mirror's profit warning, shares in the newspaper firm, which also publishes the Daily Record in Scotland, had been trading at around 160p before collapsing. They closed at 109p on Monday after the trading update.
Trinity Mirror has been hit hard by the collapse in classified advertising and the credit crunch, as advertisers scale back their adspend. It said that the economic outlook was "very uncertain".
Its shares have dropped steadily this year, having been valued at around 340p in January. They were still worth around 310p in April, before they began to spiral unceasingly downwards.
It also emerged yesterday that Trinity Mirror called a "temporary halt" to its graduate training scheme for Mirror Group, which has withdrawn interviews offered to graduates who would have worked on its national newspapers.