Underlying Asset Performance: BRNL.LSE tracks the MSCI UK IMI Select SRI Screened Index. Therefore, the performance of the constituent stocks within that index directly affects the ETF's price. Positive performance of these underlying UK companies generally leads to an increase in the ETF's value, and vice versa.

Supply and Demand: Market demand for the ETF units influences its price. Higher demand typically drives the price up, while increased selling pressure can push it down. This is especially pertinent during times of market volatility.

Expense Ratio: The ETF's expense ratio, the annual cost of managing the fund, indirectly impacts returns. While not directly influencing the daily price fluctuations, a higher expense ratio gradually erodes the ETF's value over time, affecting its long-term performance and attractiveness to investors.

Foreign Exchange Rates: As the ETF invests in UK companies but is traded internationally, currency fluctuations between the British Pound and other currencies can influence its price, particularly for investors holding the ETF in a different currency.

Market Sentiment: Broad market sentiment towards UK equities and the overall economy can influence investor appetite for BRNL.LSE. Positive sentiment tends to boost the ETF's price, while negative sentiment can lead to selling pressure.