the stock and bond of a company is known as capital structure arbitrage. When you extend this from a company to the entire country’s economy, you have the arbitrage between stock market and bond market.
There are three kind of arbitrage: pure arbitrage, near arbitrage, and speculative arbitrage. The kind of arbitrage we are talking about here belongs to the third kind, the speculative arbitrage. The are people who think only the pure arbitrage should be called arbitrage. But that’s just a matter of semantics.