Dgraph Note

  1. dgraph live -c
    The default configuration of -c (concurrent transaction) is 100, which significantly slows the speed of data importing.



  1. 平均用户游戏活跃时长为1-6个月





  1. 艰苦创业的阶段,此时创始团队是整个公司的前进动力,创始人是拉车的人

  2. ADR (American Depository Receipts)

  3. ADS (American Depository Share)

  4. 在美国上市的外国公司不需要提交季度财务报告

  5. PE/PB/PS


  6. Form 20-F Annual Report
    Form F-1 Registration Prospectus

值得注意的是,美国多层次的场外交易市场为退市机制提供了后续通道。美国上市公司从一个市场退市后,除了进入破产程序的公司,大多数公司可以退到场外交易市场证券市场上挂牌。该OTC市场主要由OTCBB(店头报价公告栏市场)和PINK SHEETS(粉红单市场)两部分市场组成。二者一个较大的区别在于挂牌标准不一,退市公司可以根据自己的意愿选择到哪一个市场去挂牌。

Telegram Notes

Bot Api

  1. No "join group" api provided
  2. Group admin can set whether to allow entrance of bot account

Cash Flow

  1. CPC ad link is a potentional revenue source


  1. 金融交易的本质是Asset Re-allocation
  2. 判断新事物可跟进性的标准是是否有可能从中盈利
  3. 局势决定市场情绪,市场情绪决定价格走势
  4. 技术应用离变现的距离决定是否值得投入

Financial Market Modelling

Stock market is a game market in which asset re-allocation happens everytime. It is interesting that stock market functions both as a place of capital investment and financial arbitrage. Initial share offering (IPO) pumps money into the market. Stock trading is an exchange between corporation and the investors. Stock trading between investors does not affect the balance sheet of the corporation.

"Money inside the market" refers to the overal valuation of the stocks in the market. It is the circulation of currency in the market. The circulation of currency happens together with the circulation of stocks.

There are many historial patterns of the market both in long-term and short-term, paired with economy patterns.

Asset valuation is a subjective, opinion based process substantially affected by human bias. Investor irrelationality is the basis of stock market arbitrage.

The flucation of stock prices is directly caused by trading orders, which is caused by the following two factors (independent of each other, but may function jointly to determine the bid/ask price):
1. The news of the corporation (fundamentals of the company)
2. The bid/ask of other market participant (the movement of other players)

Stock market has two functions, asset valuation and medium of exchange.

Bid-ask Spread

Unmatched ask price (monetary unit in currency in exchange of stock) is always higher than bid price, the difference between ask price and bid price is the bid-ask spread.

Supposedly, the bid-ask matching system will execute a trade when the price of sell order is equal or lower than a buy order. The execution price will be the price of the sell order, as it satisfies the monetary requirement for such trade, meanwhile potentionally saves money for the buyer.

The executation price will always be the ask price.

Special Thoughts

how to deal with situations when team members are not qualified enough to do the job on schedule, is a problem faced by many mangers in technology field. It is not without budget to hire qualified developer, but not enough prospective canadaicates to interview with. The technology industry is experiencing dramatic shortage in skiled manpower.


在大牛市背景下,做空交易的成功率显著降低,优质科技股的Intrinsic value保证的大跌的低可能性,牛市背景的看多情绪蔓延推高股价。另外,天然的通胀率也保证的股市市值的放大。


fluid intelligence and crystallized intelligence

Order Book Matching Algorithm


Financial Investment

Algorithmic Trading / Automated Trading

Development Environment Version Control

  • OS

    Ubuntu 14.04.2 LTS Kernel: Linux 3.13.0-52-generic

  • Python

    Python Distribution:

  • Compiler

    GCC version 4.8.2 (Ubuntu 4.8.2-19ubuntu1)

  • Scala


  • Apache Spark

    Version: 1.5.2 with Java 1.8.0_40

  • Java
    Java 1.8.0_40, JRE(Build 1.8.0_40-b25), JVM (64bit, build 25.40-b25, mixed mode)

  • Gogs

Git Study Note

  1. GIt add
    The files added to the staged area once will be tracked for any modification in later usage, but still need to be added to stage the changes in later operations.