Corporate bond spreads are now trading at their tightest levels since 2007. Bloomberg's global credit index shows OAS hovering around 103 basis points—the lowest we've seen in nearly 18 years. Even junk-rated bonds are near 2-decade lows on the spread front.

What's driving this? Heavy issuance is part of the story—roughly $435 billion of bonds hit the market in just the first half of January alone. Capital's flowing, demand is strong, and pricing looks aggressive.

But here's where it gets interesting. Major money managers like Aberdeen and Pimco are sounding the alarm. Their take: we're seeing too much complacency in the market right now. When spreads compress this hard and investors aren't demanding enough premium for risk, it usually means something's off with the pricing equation.

The parallel to 2007 is hard to ignore. Not saying we're headed for a repeat, but the historical precedent should make anyone pause and think about what happens when credit conditions tighten after running this lean.