We will try to explain how to ensure account security in exchanges, how to keep our money and account safe in crypto exchanges where we operate online.                                                                                                                     

1 - First of all, if we trade on more than one stock exchange site, we should not register with each email on the same stock exchange site with the same email. Generally, all exchanges keep your password encrypted and secure, but for example if you are exposed to phishing attack, this email and password are learned by this fake site and the people behind it, while your email and password on the non-fake site are learned while this password and email binary are found on other exchanges. Login will be attempted because it is registered. The same ones are logged in and crypto coins can be withdrawn.

2- The password in order not to be exposed to phishing attack, please pay close attention to the address of the site you are logging in, people are deceived with fake or similar addresses and password information is obtained by email.s of your email addresses are secure (upper case letters and symbols must be minimum 8 digits password must be selected) and if possible, your email addresses must be protected with a 2FA security code, except for cell phone number verification. Recently, some information has been discussed and spoken on forum sites, although it has not been fully confirmed about trying to withdraw money by entering the e-mail addresses and withdrawing the accounts by copying the sim card in some exchanges.
Source: https://bitcointalk.org/index.php?topic=2684045.0 (You can look it up by translating it into English.)
Since 2FA verification is entirely unique to your phone, it is an almost impossible protection method. In the case of removing the above mentioned sim card, there is probably a much more complicated event. In the case of removing the above mentioned sim card, there is probably a much more complicated event. 
To get detailed information for two-step verification, you need to visit the Google What is 2-Step Verification link and find out.

                                                     

3- Local exchanges or foreigners are required to keep our credentials offline (ie not open to the internet) and encrypted with encryption. It is a very important issue. Local stock exchanges should increase security measures. Because the bitcoin and crypto money market is more recently known in our country and the transaction volumes are increasing day by day. In any vulnerability, many people will suffer financial losses and the market development may be adversely affected by a distrust in the market. In this regard, we invite local stock exchanges to be much more meticulous. 

4- You should transfer the cryptocurrencies that are financially valuable to cold wallets or usb wallets and we recommend that you keep them in a safe place. We are also starting to prepare our article on this subject.

5- We recommend that you do not keep a huge amount of crypto money on local exchanges for too long. If you are not going to trade continuously and plan a long term investment, keep your crypto coins in a secure wallet. However, during the transition to TL, we should transfer it to the local stock exchange and we recommend that you transfer it to your bank by giving the required commission.

One of the most used Crypto Money Wallets on the market and entering the Hardware Wallet class is the device called Ledger Nano S. We recommend purchasing this device for maximum safety. In addition, the device not only supports Bitcoin Wallet, but also supports about 30 cryptocurrencies in total, along with recommended altcoins such as Litecoin, Ethereum, Ethereum Classic, Monero, Dash, Zcash, Ripple. Click here to buy this device from its manufacturer site.