The consensus was based on closing prices last Friday. The median is the middle of the range of target prices estimated by brokerage houses.
Of the 36 securities, 15 had an upside gain of more than 10 per cent.
According to the consensus, Thai Tap Water Supply, Thailand's largest privately owned tapwater producer and distributor, offers the biggest upside gain in the SET50 Index.
The company had a median target price of Bt5.60, while its share price at the close last Friday was Bt4.18, representing a 34-percent upside gain. Its highest estimate was Bt6, with the lowest at Bt4.50.
The consensus estimated that the stock would have a dividend yield for 2009 performance at 5.5 per cent.
Hana Microelectronics' market price at the close last Friday was 21.6 per cent lower than the median target price of Bt23.11. The top-end target price was Bt25, while the lowest was Bt19.40.
The consensus forecast that the leading integratedcircuit packager would yield 5.2 per cent in dividend for this year's performance.
Bumrungrad Hospital, Thailand's leading highend hospital operator, was the third most undervalued stock in the SET50 Index with an upside gain of 20.8 per cent from its median target price at Bt32, and highest and lowest target prices of Bt37.75 and Bt21, respectively.
The stock was estimated in the consensus to yield a dividend of 3.2 per cent.
PTT Exploration and Production had a 19.5percent upside gain from the median target price in the consensus at Bt175, with the highest at Bt205 and the lowest at Bt149.
Precious Shipping's share price at the close last Friday represented an 18.4percent upside gain from the target price of Bt21.20.
Dusit Medical Services was 18 per cent lower than the target price at Bt28.80. The stock is expected to yield 2.5 per cent in dividend for this year's earnings results.
Bangkok Expressway had a 16.3percent upside from its target price of Bt21.75.
Ratchaburi Electricity Generating Holding's share price at the market close on September 25 offered a 15.8-percent upside gain from the target price of Bt43.70.
Bangkok Bank, Thailand's largest bank by assets, had a 14.3percent upside gain from the target price of Bt136.
Another two large banks Krung Thai Bank and Kasikornbank - were 13.2 per cent and 12.6 per cent, respectively, lower than the target price.
In the consensus, KTB's median target price was Bt10.30 while Kasikornbank's was Bt91.50.
Thai Union Frozen Products had a 13.9percent upside gain from the target price of Bt29.62.
PTT, the SET's biggest marketcap stock, was 12.2 per cent lower than the median target price of Bt294, with the highest target price of Bt353 and the lowest of Bt208.
BEC World and Thoresen Thai Agencies had upside gains of 11.3 per cent and 10.3 per cent from the target prices of Bt24.16 and Bt28.95, respectively.
Among stocks in the SET50 Index, TMB Bank was 30.4 per cent higher than its median target price of Bt0.84. However, its share price was below the highest target price of Bt1.35.
Thai Airways International was 20.5 per cent overvalued from its tarฌget price of Bt17.80.
ItalianThai Development's share price at the market close last Friday exceeded the target price of Bt3.12 by 17.5 per cent.
PTT Aromatics and Refining was 11.9 per cent higher than its target price at Bt22.90.
However, the stock is predicted to offer an attractive dividend yield of 4.2 per cent for this year's performance.
Thanachart Capital is another overvalued stock when considering the target price at Bt15.10. It was 11.7 per cent higher than the target.
However, its dividend yield estimate of Bt5.70 per cent for this year's finanฌcial results is seen as handsome.
IRPC and PTT Chemical were 9.9 per cent and 7.7 per cent higher than the target prices of Bt4.11 and Bt72, respectively.
Speculation about parent PTT's plan to integrate its four oil refinerฌies and petrochemical arms has been the major driver for these two share prices' strong gains. The plan is undergoing a feasibility study, which is expected to be completed by the end of the year.
IRPC, PTT Chemical, PTT Aromatics and Refining and Thai Oil are the four units being considered for integration.
Esso (Thailand), Siam City Bank, CP All, Charoen Pokphand Foods, Minor International and Airports of Thailand were overvalued last Friday in relation to their median target prices.
Their share prices on September 25 exceeded the targets by between 0.6 per cent and 3.4 per cent.
In terms of dividend yield, Esso is estimated in the consensus to offer the highest yield among its peers in the SET50 Index - at 8.6 per cent.
Thai Plastic and Chemicals and Siam Makro are expected to provide yields of 7.3 per cent and 7 per cent, respectively.
MCOT, the TV Channel 9 operator, is estimated to yield 6.8 per cent, ahead of the estimated yield of 6.7 per cent from Electricity Generating and that of Advanced Info Service at 6.6 per cent.
Charoen Pokphand Foods is estiฌmated to yield 6.4 per cent.
Delta Electronics and Bangkok Expressway are expected to give the same yield of 6.3 per cent, while 6 per cent is predicted for Thai Union Frozen Products.