I.up [美 əp, 英 ʌp]副up often appears as the second element of certain verb structures in English (back up, pick up, sit up, etc). For translations, see the relevant verb entry (back, pick, sit, etc).
She formulated an investment strategy to which she stuck throughout her life: conservative investments, substantial cash reserves to back up any movement, and an exceedingly cool head amidst turmoil.
When a traditional deposit bank provide loans such as business lending, mortgage, overdraft or credit card, they are stuck with the borrowers for years or even decades.