  This study delves into the temporal dynamics within the equity market through
the lens of bond traders. Recognizing that the riskless interest rate
fluctuates over time, we leverage the Black-Derman-Toy model to trace its
temporal evolution. To gain insights from a bond trader's perspective, we focus
on a specific type of bond: the zero-coupon bond. This paper introduces a
pricing algorithm for this bond and presents a formula that can be used to
ascertain its real value. By crafting an equation that juxtaposes the
theoretical value of a zero-coupon bond with its actual value, we can deduce
the risk-neutral probability. It is noteworthy that the risk-neutral
probability correlates with variables like the instantaneous mean return,
instantaneous volatility, and inherent upturn probability in the equity market.
Examining these relationships enables us to discern the temporal shifts in
these parameters. Our findings suggest that the mean starts at a negative
value, eventually plateauing at a consistent level. The volatility, on the
other hand, initially has a minimal positive value, peaks swiftly, and then
stabilizes. Lastly, the upturn probability is initially significantly high,
plunges rapidly, and ultimately reaches equilibrium.
