Since the IB Gateway is Java-based, it seems that the only way it would accumulate a lot of memory would be if the messages that it sends are not immediately released after being received by the reader.? I suspect that they optimized the gateway for responsiveness and defer garbage collection to prioritize responsiveness.? Since I occasionally use the Gateway to pull strikes and expirations once every week or two on a list of about 500 stocks and ETFs, it stays busy for a while...but still, it shouldn't take that long to do garbage collection and seems that they could use a parallel garbage collector.? In any case, I worked around my issue for now by just giving it a lot of memory.? Just curious if there was an additional call I was supposed to make to cause the gateway to release messages / free up memory.? I think TWS and Gateway offer a lot of good features.? Definitely think Java was the right language choice in order to make it cross-platform.? But as a Java developer, it just feels a lot slower and bloated than it should be.? I think the codebase could be cleaned up a lot and made to run a lot faster and more efficient.