lost the least, housing bubble, scaled a new peak

[user_gary]

Losing out in a big way is DLF's K P Singh and family that has seen its net worth erode more than 67 per cent and give way to promoters of Bharti Airtel - Sunil Bharti Mittal and family - to the third slot on list of India's richest. Shares of Bharti Airtel have lost the least among the top companies.
The realty sector has been the hardest hit, since the a housing bubble in the United States got worse and roiled stock markets worldwide. Unitech share prices have fallen by 76 per cent since the stock market scaled a new peak on January 10.



Please explain the emboldened parts to me.

[Anglika]

lost the least = have not lost nearly as much in money as the others

housing bubble - The cost of housing in the US has been rising very fast, but it is based on poor funding methods so prices have been growing like a bubble, but this situation is about to burst and collapse.

scaled a new peak = reached a high level