This is the 16463rd most frequent Russian word.
рынку
"рынку" means "market" (dative form).
The word "рынке" (dative case) is used to indicate the location where the action occurs, referring to the market.
На рынке продают свежие овощи.
At the market, fresh vegetables are sold.
The word "рынку" (dative case) is used as part of the phrase "к рынку" to signify direction or movement towards the market.
Мы идём к рынку за фруктами.
We are heading to the market to get fruits.
Here, "рынке" (dative case) indicates the location related to the context of price changes occuring at the market.