A CONTINUING influx of foreign cash could push the Hang Seng Index up further this week, despite doubts whether the unexpected rally can be sustained. Last week's 885.66-point surge in the Hang Seng caught investors by surprise, despite evidence that US interest rates have peaked. Brokers believe the index may rise by another 100 to 200 points early this week, but a correction over the short term is expected. Samuel Lau, research director at Seapower Securities, described the influx of funds as 'hot money' which would not remain in the market for long. The Hong Kong market's fundamentals remain the same despite last week's strong turn in sentiment, which triggered heavy buying. Daily turnover rose to $8.35 billion on Thursday and almost $10 billion on Friday. Three elements govern the direction of the local market: interest rates, corporate earnings and China's economic and political factors. Mr Lau said interest rates were the only factor that had sent a positive signal to the market. 'Corporate earnings are unlikely to have big changes while the China factor may bring negative sentiment to the market,' he said. He predicted the earliest that US rates would be cut would be the third quarter. Philip Chan, research director at Shanghai International Securities, said corporate earnings growth for 1995 would be about 12 to 15 per cent. 'We anticipate a market recovery with the peaking of US interest rates, but not that fast and strong,' said Mr Chan. In three days last week, the index had risen more than 10 per cent, he said. Standard Chartered Securities warned investors to keep an eye on the potential effect the ongoing anti-corruption campaign being waged in China may have on the Hong Kong bourse. Neither brokerage has readjusted its market forecast for 1995. Both maintain that the index will reach 9,500 to 11,000 by the end of the year. Standard Chartered Securities expects the index to hit at least 10,500 before the year is through. The brokerage suggested the market could rally another few hundred points, with the best bets on more interest-rate-sensitive stocks, such as Cheung Kong and Henderson Land.