Hey guys, this is Hummingbot.
Just to add a point to this post: Legit market makers will never try to manipulate the price. Market makers will improve the depth of the order book, and enable price discovery, both are the results of higher liquidity. If you are an ordinary trader, you'll want to trade in a liquid market because only in that market can you buy/sell your asset at a reasonable price easily and fast. In an illiquid market with only a few participants, you may have problem selling an asset at a price higher than your buy price or vice versa.
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