As there are too many icos to choose attentively and wisely, I prefer not to bother myself with all of them and only check out the ones really discussed on the forum. Yet I don't invest in one even if I like it. I wait till the coin is released and appears on the exchanges. Then I wait for some time and see how it goes in terms of the price and if it is not going down, I buy. It's pretty rare for a coin to grow instantly after ICO, you the chances of you losing something with this strategy are low and it makes you safe from scamming.

ERC-20 is the service I use most often for my tokens and to keep Ethereum themselves. Of course it would be a mistake to say that I kept a very high amount of money, but I can easily say that I use it extensively and that I am satisfied with this service. I do not yet have a security problem on my own but I do not want to go through without telling some friends around me that I have minor problems. Although I have friends who are not satisfied with this service around the time, I think it is quite handy and reliable for transactions up to a certain amount.

I do not think there is a situation to be panicked, feared or frightened because it is extremely normal to have such situations for the period we are in. Of course, the very low end of the price level is not unusual, and depending on the upsets we have seen over the past year, these price levels are not at all normal, but the bear market is very influential. Moreover, the only reason for the price decline and the only criminal are amateurs, ignorant and excited investors. These investors, who make simple mistakes in the current downtrend trend and are caught in panic, also support price decline. The only reason why informed investors are not drowned in these fluctuations is because they must not act in panic and know how to behave in such situations.

I want to start by stating that it is possible to answer this question with various reasons. First, there is one detail that needs to be known, that in recent times the market volume has dropped to a very low point, which is reflected in the prices of all cryptocurrencies. Ethereum has also suffered price declines due to this distress and it is still alive. Another reason is that it is now a drop in participation in ICO projects. Demand for Ethereum has also begun to decline, with fewer participation in these projects. Of course, this is not the biggest factor, but it should be noted that this factor is also a serious effect on the price. Another reason for the price to fall is the intense sales and intensive buying orders made by the investors we call whales. These investors gradually reduce prices and fill their own pockets after each decline. So to summarize, these prices have plenty of reasons, it would be erroneous to show one reason or to link price decline for a single reason.

IDEX is legit because this is the best DEX exchange on market right now I think. Maybe this is not so simple to make an exchange there if we mean usability but they have a lot of altcoins and also you can use Metamask for trades. I usually do that. After Etherdelta I don't use private keys. This is not very convenient  market place if you trade les than 0.1 eth . So don't try to trade there with low deposit.

Right now, it is difficult to do day trading because the market it makes me confused, and if I want to buy one coin that is in the down price, I need to take a look deeper and determine if the price can increase in the next hours or not. yesterday, I almost stuck in the high price but fortunately, I can sell the coins once it reaches the high price than I bought so I can make a small profit and leave the market for a while. but I prefer to hold the coin for a while and will see if the market can be back normal in the next weeks.

You may HODL if you buy bitcoins and intend to hold for a very long period of time. Let's assume you bought bitcoins and you intend to keep it for about two years, then you may HODL.
However, if you intend to make profits, however small, in a very short period of time, then I'd advise you to day trade. Day trading is simply taking advantage of the differences in the price of bitcoin in short tine intervals.  You however need to be very careful because it might be risky.