invisible market meaning in Chinese

无形市场
隐形市场

The author then goes on to a thorough discussion on the two forms this market has taken - the invisible market and the auction market . topics included here are : their transaction features , participants " behavior patterns and price making mechanisms
第三、四部分一级半市场分析：无形市场与拍卖市场根据交易方式、价格形成机制以及市场参与者等的不同，一级半市场可以分为无形市场和拍卖市场。