BrokerageAccount account = checkAccountAuthorization(
getUser(username), accountId, BrokerageAccountPermission.Trade);
// Check if the symbol is valid
if (this.referenceDataService.lookup(params.getSymbol()) == null) {
throw new InvalidSymbolException();
}
// Place order
Order order = account.placeOrder(params, marketDataService);
exchangeTradingService.placeOrder(order);