Nowsdays, banks in HK offer 2 types of mortgage loan rate: Prime (P) and HIBOR (H). Current P are either 5.00% (HSBC, Bank of China and Hang Seng Bank) or 5.25% (all others). They normally quote P-1.25%. Therefore, mortgage loan interest cost for you become 5.25%-1.25% = 4%. The prime rate can be adjusted but not very frequent. On the contrary, H is floating everyday as it is fixed everyday by different banks. Bank normally quotes 3 month HIBOR + 0.5%, which was certainly lower than 4% as 3 month HIBOR today was fixed at 1.10%, that means 1.6%. However, you must bear in mind that HIBOR is very volatile and beat up to 20% in 1997! Therefore, HIBOR plan is much more risky than P plan.