Found 2 exchanges where Siacoin is traded for EUR. According to the data on 30 August the most optimal price to exchange SC for EUR is €0.00058 for 1 Siacoin. This rate is fixed at Kraken at the maximum trading volume of the pair SC/EUR - 17.6 ths. EUR.
The maximum daily trading volume is observed in the SC/USDT trading pair at Poloniex and reaches € 1 482 091 (0.194% of the exchange's total trading volumes) at the price € 0.00055 per 1 SC.
The minimum price to buy SC for EUR is 0.00053 - on the exchange Bit2Me.
The maximum price to buy SC/EUR is 0.00058 - on the exchange Kraken.
Warning: some SC markets show an abnormally wide spread — those quotes may be unreliable (thin liquidity or off-market trades). Cross-check the volume against several venues.