Hanny Holdings and Hung Hing Printing Group are two companies that have seen heavy buying in recent months.
Director C.H. Yam bought 1.32 million Hung Hing shares worth $7.2 million on August 14, undeterred by the 32 per cent increase in the share price since last month from $4.10 to $5.40.
His latest acquisition follows a similar purchase of 2.3 million shares in the last week of June at $4.39 a share.
For directors and major shareholders, Hung Hing has long been a buy. In the past two years, only one insider sell transaction was reported to the stock exchange.
Earlier this year director Matthew Yum took profits on about 10.5 million shares worth $38.6 million after doubling his money.
The disposals were made on April 3 and 4 at $3.50 to $3.85 a share. Before the disposal, Mr Yum had acquired a net 11.76 million shares from May 1994 to March this year at $1.84 a share.