A substantial shareholder notice has solved the mystery of the 1 million Corporate Travel Management shares which changed hands via broker Morgans on Friday.

Hyperion Asset Management has ceased to be a substantial shareholder (falling below the 5 per cent threshold) on August 30, an ASX filing late this afternoon shows.

Hyperion had previously been identified as holding 5.04 per cent of the hedge fund target's shares. Corporate Travel Management rose 4¢ to $17.87 on Tuesday. The 1 million-share block was traded at $17.75, according to The Australian Financial Review's Rear Window column.