Explanation

The bond's net return factors in its price change, coupons paid, and financing costs over the period. The calculation involves several steps:

Step 1: Reinvest the first coupon

• Coupon received on September 30: BRL 27,500
• Reinvestment rate: 3.0% from September 30 to December 31
• Future value of first coupon: 27,500 × (1 + 3.0%) = 28,325

Step 2: Calculate financing cost

• Purchase price: BRL 1,062,500
• Financing cost: 3.5%
• Total financing cost: 1,062,500 × 3.5% = 37,187.50

Step 3: Calculate net return for the 6-month period

• Closing price: BRL 1,048,200
• Purchase price: BRL 1,062,500
• Price change: 1,048,200 - 1,062,500 = -14,300
• Second coupon: BRL 27,500
• Future value of first coupon: BRL 28,325
• Total cash flows: -14,300 + 27,500 + 28,325 - 37,187.50 = 4,337.50
• Net return: 4,337.50 / 1,062,500 = 0.4082%

Step 4: Annualize using semi-annual compounding

• 6-month return: 0.4082%
• Annualized return: 0.4082% × 2 = 0.8165% ≈ 0.82%

The calculation properly accounts for all cash flows including price appreciation/depreciation, coupon payments, reinvestment of coupons, and financing costs to arrive at the correct net return.