May I know if my fund will be protected in case of the broker stop operating ?

https://www.ottofxtrading.com/

OTTO FOREX is an unregulated broker and should be avoided at all events. OTTO FOREX claims to be owned and operated by Otto Forex Global Limited, a licensed entity supervised by the US National Futures Association (NFA).

We indeed found a matching result in NFA's registry, however, OTTO FOREX is not overseen by the regulator as it is not an approved member of the regulator. Please be informed that if a broker claims to be eligible to solicit US customers in forex activities, it must: 1) be accredited as an approved Forex Dealer Member of NFA; 2) be admitted as a "retail forex exchange dealer." Obviously, OTTO FOREX doesn't satisfy these conditions. That means, this broker is merely a registered firm rather than a regulated one and is not qualified to carry out such services. 

What's worse, the Spain regulator CNMV and the UK regulator FCA have successively added OTTO FOREX to the alert list to warn the public that this firm is not authorised to provide the investment services in their countries. You can check the full or warning from CNMV and FCA against OTTO FOREX respectively.

Our verdict is that OTTO FOREX is thoroughly a scam on account of running its business without any relevant license approved by a reputable regulator. Therefore, we would recommend traders stay away from this broker and trade with licensed brokers.