It is arguable to say which market is over-valued, just like no one really knows the market goes up or does down in the future. But we can say which market is more over-valued as compared with other markets using PE. I did a quick scan of a few world markets. Here is I see today: 1. US median PE 18.18 (321 stocks valued over 1B USD); 2. Shanghai/China median PE 52.63(1045 stocks valued over 1B CNY); 3. Shenzhen/China median PE 71.43 (652 stocks valued over 1B CNY); 4. Taiwan median PE 11.23 (401 stocks valued over 1B TWD); 5. Hongkong median PE 11.76 (601 stocks valued over 1B HKD); 6. Japan median PE 16.95 (472 stocks over 10B yuen); 7. London median PE very big (actually from the data available to me per-dollar earning is zero) based on 247 stocks over 1B GBP (need to double check); 8. Singapore median PE 12.34 (96 stocks over 1B); Just considering PE, no surprise to see China stocks goes down another 50% and still over-valued as compared with US/Japan/HK/TW markets. As for US, looks like the value over PE is not high. So, it is a lot more fun to see how China stock market will go in the near future.