I've been growing my HIVE/HBD investment before it was even HIVE/HBD. I've been very impressed how stable HBD is, very rarely going under the peg, sometimes above it. HIVE has been a rollercoaster and when it "pumps" I believe it's reaching it's natural baseline. But people are in a habit of earning HIVE and selling it for other currencies, which artificially keeps the price low. All it would take is a reason for them to break that habit and power up HIVE instead of selling - that would stabilize HIVE and assist HBD staying on peg.
For me the attraction of HBD is not just APR interest, it's the ability to quickly and easily buy/sell between HIVE. Earn HIVE and when HIVE is around $0.50 - $0.60, sell it for HBD, when it's $0.25 - $0.30 buy it and stake it. Then next time it's $0.50, you'll see a nice additional profit from that cheap HIVE purchase sitting in stake. On top of that, HIVE stake grows almost 3% APR while sleeping.
RE: How Safe Is USDC As An Investment Over HBD?