China's EV giant overtook Tesla in unit sales last year, but margin pressure, overseas risks and a controversial financing model raise questions on whether it can still deliver shareholder valueKey Takeaways:BYD's global sales surge has not translated into higher profitability, as the company faces pressures from an ongoing price war at home and falling profits per vehicleThe unwinding of the leading EV maker's supplier‑financing scheme and rising overseas challenges threaten to lift its debt ratio and damp ...