semiconductor chips are seen on a circuit board of a computer in this illustration picture taken february 25 2022 reutersflorence loillustration shanghai aug 5 reuters  chinese chipmakers shares jumped by the most in two years this week as house of representatives speaker nancy pelosis visit to taiwan heightened tensions with the us driving patriotic bets on a sector beijing sees as key to its rivalry with washington the surge in interest in chipmaking stocks which had lost more than a third of their value over the past year on valuation concerns came after the us senate last week passed the chips and science act to better compete with china read more chinas semiconductor index csih30184 rose 68 on friday to a fourmonth high bringing the weeks gains to 142 the best weekly performance since mid2020 although the us chip act would further restrict the use of advanced us technologies in china while prodding more semiconductor investment in the us some investors interpret it as good news for local chinese players domestic chipmakers will have huge opportunities to replace imported products said niu chunbao director of investment at private fund house wanji asset adding local players could see explosive growth this view was echoed by guorong securities which said in a note that the us chip act will stimulate the development of chinas semiconductor industry shares in shenzhen china micro semicon co ltd 688380ss soared 82 on their first day of trading in shanghai in contrast with weaker recent stock market debuts chinese chipmaking giant semiconductor manufacturing international corp smic jumped 71 in hong kong and 44 in shanghai  the sse star chip index starchip surged 83 but chinese chipmakers are expensive compared with their global peers at a time when the prospect of a global economic recession threatens chip demand the global industry which suffered from supplychain snags during the height of the covid19 pandemic now faces weak demand as inflation and recession fears reduce orders for chips used in everything from cars to mobile phones chinas sector trades at around 57 times earnings and remains the priciest sector in chinas stock market reporting by jason xue samuel shen and brenda goh editing by alexander smith