。
The luxury goods market is growing rapidly.
Literal
Luxury-goods [possessive-の] market [topic-は] rapidly growing-[state-ている].
A business-report style sentence. 贅沢 (ぜいたく) is 'luxury, extravagance'. 贅沢品 ('luxury item') uses the suffix 品 for 'goods, item'. 急速に ('rapidly, swiftly') is a formal adverb. 成長する ('to grow') is used both for biological and economic growth. ~ている expresses the ongoing state of the market being in growth.