According to researcher Michael A. Gayed, lumber prices give insight into economic downturns. It directly affects the housing market and the housing market the broader economy. And right now, lumber is looking pretty dismal.
Source: https://www.msn.com/en-us/money/savingandinvesting/housing-market-crash-alert-why-investors-should-pay-close-attention-to-lumber-prices/ar-AA1aNHcB