Bond Market is the most important to monitor while investing and making macroeconomic desicions. Inverted bond yeld curve is when short term bond yelds are greater than long term ones and this is a signal of fear for an imminent recession and disaster like a vulcano's eruption The indicatior is applied to US Bond market but you can try to other countries like EU, China and so on. The code is free. No further word is more powerful than a clear image as following: