China's tanking stock markets were largely overshadowed due to turmoil in Greece over recent weeks, but the impact of tumbling share prices is getting harder to ignore. China's leading Shanghai Composite index has fallen by over 30% over the last 3 weeks. The collapse has largely been contained within China so far, but there are signs that it's starting to impact other markets. Oil prices dropped 7.8% overnight to as low as $52.48 (£33.85) a barrel — the biggest intraday move for crude oil since February and the lowest price for WTI crude since early April. Accendo Market's Mike van Dulken says, what he's calling, the "Great Fall of China" is behind the oil drop. Tanking Chinese stocks have "solicited continued concerns about demand from the world’s number 1 basic materials consumer." We're seeing the same impact on copper, which has fallen to a 5-year low over the past 2 trading sessions. "The Great Fall of China" doesn't look like it will stopped anytime soon either. The Chinese government's numerous attempts to prop up prices haven't done much so far and Citi said Monday that shares have further to fall. Deutsche Bank backed that view Tuesday, with analyst Nick Lawson saying in a note: "Bubbles have a nasty habit of reverting back to and beyond the mean." Chinese companies have decided to take matters into their own hands and they just found a better and easier solution — suspend the companies' stocks from being traded at all. That means commodity prices could be in for further pain, which in turn could hit stock markets around the world.Join the conversation about this story » NOW WATCH: 6 mind-blowing facts about Greece's economy