Tourism Holdings says it is not in any breach of market rules despite a rise of almost 18% in its share price on Thursday.
Shares in the listed tourism operator hit 80 cents, an increase of 12c.
The NZX has written to Tourism Holdings, asking for disclosure of any information to the market that might explain rise.
In repsonse, chief financial officer Ian Lewington says Tourism Holdings is in compliance with all the rules.
The camper van manufacturer's share price fell 1c cent to 79c on Friday morning.
Its six monthly results will be published in February.