mất tiền, lỗ = a company or organization that is in the red has lost money in a particular period:
Business is really going poorly these days. We've been in the red for the past three months. Tình hình kinh doanh đang tệ đi. Chúng ta thua lỗ trong ba tháng qua.
Currently, the group is in the red by $1.7 million.