The idea comes from a frustration of lack of simple, intuitive, fast and free stock/crypto trade simulator.
I still use simulator from Investopedia. However, their stock data feed is delayed by 10-15 minutes. It means it is not a proper simulator since one can easily game the system.
The best simulator I have used was tradefix.io, it was fast enough and had simple, intuitive interface. However, it went AWOL after one and half year.
There are few free stock simulator, however, they are not simple, intuitive, fast and user-friendly at all. Some brokerage houses have simulator, but one has to open account.
The best available crypto-simulator is 
As popularity of cryptocurrency is rising in all over the world and in futures, most of the top securities (i.e stocks) will be tokenized, there will be millions of traders in the world. However, most of them will not have proper education and background to profit from their trading. Therefore, a free, fast and user-friendly stock/crypto simulator will be required. Therefore, 
All these simulators lack monetizing idea. In case of niffler.co, they are trying to make a model where patrons will support a trader to learn from his skills. However, there are lots of questions to that whether they will attract pro-traders to simulate and amateur traders will pay to learn.
Stock and crypto simulator on Steem chain using TRADE token
A simulator that will be able simulate both stocks, commodities and cryptocurrencies, will be built as DApp on Steem chain. TRADE tokens will be created from 
When a trade position will be open by the trader in simulator DApp, it will be posted on the Steem-chain along with value of total portfolio (e.g. no. of stocks, no. cryptos, fiat balance). When position will be closed it will be posted along with updated portfolio. Users will be able to create as many as new portfolio as they want and perform as many as trades they want similar to post and comment.
Users based on their performance will be awarded with TRADE tokens. TRADE tokens will be traded in future Steem based exchange.
Few ideas about monetizing the DApp or create value for TRADE token.
DApp will have adsence/sponsor to make it sustainable. If any profit left after the maintenance, then TRADE tokens will be purchased from the market to provide it value, similar to BNB token idea.
Or, Simulator users will be required to use TRADE tokens to participate in simulations. Every new user will be given free TRADE tokens to start which will be sufficient to make decent number of trades. However, heavy users have to buy or earn TRADE tokens. Tokens can be earned with writing blogs, posting vlogs, commenting and simply trading (with positive outcome). Top (simulator) traders will be supported by the DApp budget since they will be blood and bones of the DApp.
The best performer will be earn @dTRADE tokens. Also, the contributors will earn tokens too by writing articles, commenting. helping others, etc.