tipping
noun [ U ]
uk/ˈtɪpɪŋ/ us FINANCE
the activity of giving advice on which shares to buy or sell:
The Financial Services Authority announced the formation of an e-commerce team to monitor tipping on the internet.
Their shares plunged further following negative comments on a share tipping website.
COMMERCE
the act of giving an amount of money to someone who has provided a service, especially in a hotel or restaurant:
In the States tipping is common.