diff --git a/src/coex/exchange_team.rs b/src/coex/exchange_team.rs
index d64ca10..113907d 100644
--- a/src/coex/exchange_team.rs
+++ b/src/coex/exchange_team.rs
@@ -5,7 +5,7 @@ use crate::coin_health_check_team::request_others::{CoinPriceData, ExchangeInfo,
 use crate::database_control::*;
 use crate::decimal_funcs::{decimal, decimal_add, decimal_div, decimal_mul, decimal_sub};
 use crate::signal_association::signal_decision::*;
-use reqwest::Client;
+use reqwest::{Client, ClientBuilder};
 use rust_decimal::{prelude::FromPrimitive, prelude::ToPrimitive, Decimal, RoundingStrategy};
 use rust_decimal_macros::dec;
 use sqlx::FromRow;
@@ -113,13 +113,12 @@ pub struct MarketCapIndex {
 
 // buy coin
 pub async fn buy_coin(
-    client: &Client,
     exchange_info_vec: &Vec<ExchangeInfo>,
     trade_fee_vec: &Vec<TradeFee>,
 ) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     let mut suggested_coin = get_suggested_coin_list().await;
 
-    if !suggested_coin.is_empty() {
+    if !suggested_coin.is_empty() && exchange_info_vec.len() != 0 && trade_fee_vec.len() != 0 {
         let server_epoch = server_epoch().await;
         let mut filtered_suggested_coin_vec: Vec<&SuggestedCoin> = Vec::new();
         let mut is_exist_delete_symbol: bool = false;
@@ -132,7 +131,7 @@ pub async fn buy_coin(
             // 600_000 (600 secs = 10 mins)
             {
                 filtered_suggested_coin_vec.push(element);
-            } else if server_epoch - element.registered_server_epoch >= 1_800_000 {
+            } else if server_epoch - element.registered_server_epoch >= 5_400_000 { // 30mins * 3
                 delete_condition.push_str("id = ");
                 delete_condition.push_str(element.id.to_string().as_str());
                 delete_condition.push_str(" OR ");
@@ -153,6 +152,10 @@ pub async fn buy_coin(
             let mut expected_pure_profit_percent = 0.0;
             let insert_table_name = String::from("buy_ordered_coin_list");
 
+            let client = ClientBuilder::new()
+                .timeout(tokio::time::Duration::from_millis(3000))
+                .build()
+                .unwrap();
             for element in &filtered_suggested_coin_vec {
                 if is_tradable == true {
                     let lot_step_size_result = exchange_info_vec