Former Daily Mirror editor Piers Morgan bought shares a day before they were tipped in the City Slickers financial column in his paper, a court was told.
The 'City Slickers' trial is now in the third of an expected six weeks
The value of the shares then rose, but Mr Morgan was cleared of wrongdoing, London's Southwark Crown Court heard.
Prosecutors claim journalists James Hipwell and Anil Bhoyrul would buy stocks, tip them and sell at a profit.
Mr Hipwell, 39, of North London, denies breaching the Financial Services Act; Mr Bhoyrul is not on trial.
Another defendant, private investor Terry Shepherd, 36, of Leatherhead, Surrey, denies a charge of breaching the Act.
Both deny conspiring with Mr Bhoyrul to "create a misleading impression as to the value of investments between August 1, 1999 and February 29, 2000".
The alleged "share-ramping" involved 44 separate incidents.
Mr Shepherd allegedly gained a profit of £17,000, Mr Hipwell £41,000 and Mr Bhoyrul £15,000, although they did not make a profit on every occasion when a share was tipped in the column.
The reporters were sacked by the Mirror in February 2000.
Ex-Mirror lawyer Martin Cruddace was asked about Mr Morgan's involvement under cross-examination by Philip Hackett QC - defending Mr Hipwell.
Mr Hackett asked: "[Mr Morgan] purchased them on 17 January , the day before the article?"
Mr Cruddace replied: "Yes, I know."
The lawyer then asked: "He purchased £67,000 (worth)?"
Mr Cruddace replied: "I don't know."
Mr Cruddace said on three occasions he had bought shares which were tipped in the City Slickers column soon afterwards.
But he said that was a coincidence and he had intended on holding onto the stock for a long time.
"If I was in the process of misusing that information for my own gain I might have done it more than the three coincidences ... mentioned," he said.
Mr Cruddace - like Mr Morgan - has been cleared of wrongdoing in the matter.
The trial was adjourned until Thursday.