NATIONAL STEEL CO

A sensitivity analysis for risks related to interest rates is shown below. The Company considered two different scenarios to assess the impact of variations in these rates: Scenario 1 predicts a horizon of rising interest rates, and Scenario 2 projects a reduction horizon. To calculate these risks, the closing rates as of June 30, 2026 were used as a reference based on a dispersion model, which considers not only historical interest rate fluctuations but also detailed management projections.

This approach allows for a comprehensive and precise assessment of potential economic impacts arising from interest rate fluctuations.

The effects on balances in Reais related to assets and liabilities linked to interest rates, considering scenarios 1 and 2, are demonstrated below:

(*) This sensitivity analysis is based on the assumption of probability that market values as of June 30, 2026 recorded in the Company's assets and liabilities will be maintained.

(*) Sensitivity analysis is based on the assumption of maintaining market values as of December 31, 2025 recorded in the Company's assets and liabilities as a probable scenario.

The Company is also exposed to market risks related to the volatility of commodity and input prices. In line with its risk management policy, risk mitigation strategies involving commodities may be used to reduce cash flow volatility. These mitigation strategies may incorporate derivative instruments, predominantly forward, futures, and options transactions.

Below are the price risk protection instruments, as shown in the following topics:

a) Cash flow hedge accounting – Platts index

To better reflect the accounting effects of the Platts hedge strategy on the result, the subsidiary CSN Mineração opted to formally designate the hedge and, consequently, adopted hedge accounting for the iron ore derivative as a hedge accounting instrument for its highly probable future iron ore sales. As a result, the mark-to-market arising from the Platts volatility will be temporarily recorded in equity and will be taken to the income statement when the sales occur according to the contracted evaluation period. This allows the recognition of Platts volatility on iron ore sales to be recognized at the same time.

The Company has periodically reviewed market scenarios to assess its exposure to iron ore price risk to ensure adequate coverage of market price fluctuations. This process involves monitoring fluctuations and trends in global prices, in addition to considering economic and geopolitical factors that may impact the value of this commodity.

The following table presents profit and loss for derivative instruments as of June 30, 2026:

Activity related to cash flowhedge accounting amounts -Platts index recorded under shareholders' equity on June 30, 2026 is as follows:

The cash flow hedge - Platts index was fully effective since the contracting of derivative instruments.

To support the above-mentioned designations, the Company has prepared formal documentation indicating the manner in which the cash flowhedge accounting – Platts index designation is aligned with CSN's risk management objective and strategy. The hedging instruments used, itemhedged, and the nature of the risk to be hedged are identified.

The expected high level of effectiveness of designated relationships is also demonstrated. Iron ore derivative instruments ("Platts" index) were designated in amounts equivalent to the portion of future sales, comparing the designated amounts with the expected and approved amounts in the budgets of the Management and Board.

b) Cash flow hedge accounting