true); $binance = new \ccxt\pro\binance($config); $bittrex = new \ccxt\pro\bittrex($config); $symbol = "BTC/USDT"; $loop = function($exchange, $symbol) { echo 'got inside' . PHP_EOL; for ($i = 0; $i < 5; $i++) { $ticker = yield $exchange->watch_ticker($symbol); print_ticker($ticker, $exchange->id, $symbol); } }; function print_ticker($ticker, $exchange_name, $symbol) { $bid = $ticker['bid']; $ask = $ticker['ask']; echo "$exchange_name $symbol - bid: $bid <> ask: $ask" . PHP_EOL; } \React\Async\coroutine($loop, $bittrex, $symbol); \React\Async\coroutine($loop, $binance, $symbol);